Asparagus and Shiitake Mushroom Tart with Polenta Crust

Last month, I had brunch with Deborah Madison. (Ok, there may have been a few other people there, too.)

I’ve been a Deborah fan since I picked up a copy of Local Flavors at the UC Santa Cruz book store during my senior year, and proceeded to shirk my studently responsibilities – trifling matters like papers, homework, and presentations – to make everything from potage to pancakes to pandowdies. Deborah is a fellow Banana Slug, and, due to her success as a chef and writer, I can only imagine that she picked a more useful major than Art History. (Or at least, did her homework.)

Thanks to Jay for being my lovely hand model!

Deborah’s writing style is so calm, warm, and engaging, I feel like she’s been in the kitchen with me for the last 10 years in the form ofVegetarian Cooking for Everyone,Seasonal Fruit Desserts, andVegetable Soups.When I learned that she would be hosting a brunch and booksigning at Left Bank restaurant with dishes from her latest tome Vegetable Literacy, it was with great trepidation that I signed us up (and not just because of the hefty price combined with my inability to find a decent job with an Art History degree). I was still traumatized from the last time I came face to grumpy face with a culinary idol. What if Deborah turned out to a be mean and cranky? How would I ever recover?

Luckily, Deborah was as warm and gracious in person as she seems in her books. I only refrained from hugging her because I didn’t want to get kicked out before drinking the unlimited wine served with brunch. Unfortunately, she left before her biggest (and now drunkest) fan could accost her for a post-prandial photo.

As each lovely course was whisked out by the servers, Deborah said a few words about each. One of the dishes consisted of roasted asparagus spears topped with salsa verde – simple and delicious. Deborah introduced asparagus as “the queen of spring,” a title that I found quite fitting.

Lately, I’ve been especially loving the queen of spring in combination with shiitake mushrooms. Shiitakes have a lighter flavor than most other mushrooms, and their bouncy texture stands up well to cooking, refusing to go soggy like buttons or crimini. Shiitakes tossed with olive oil and salt, then roasted, are particularly addictive, and I have trouble leaving enough in the pan and out of my gullet to put in whatever dish I’m trying to make. I find the pair of them perfectly pitched, and have been enjoying them in citrusy soba salad, creamy penne with goat cheese and herbs, and brothy miso soba noodle soup. But nestled in a polenta crust and surrounded by savory custard is my favorite thus far.

I first saw the idea for a polenta crust on Guilty Kitchen, then The Wednesday Chef(adapted from Ancient Grains for Modern Meals). A quick, thick polenta, enriched with egg, a touch of butter, and parmesan, gets spread in the bottom of the pan, shaped when cool enough to handle, and baked to crisp it up a bit. It’s lighter than pastry, less fussy, and naturally gluten-free. Carey’s beautiful asparagus galetteinspired me to fan out the stalks on top and use greek yogurt in the custard in place of cream. (Also, Carey is my personal hero not only for inventing the awesomest recipes and taking the most stunning photos of them on Reclaiming Provincial, but also for telling off someone who left a rather rude comment on my Bojon Gourmet Facebook page last week. Thank you, Carey!)

I added crumbles of feta cheese and roasted shiitakes to the base. Inspired by Deborah’s love of truffle salt, I splurged on a small jar and added a few pinches to the mushrooms, which lends the tart a touch of magical, mysterious flavor.

The crust holds its shape beautifully, particularly when allowed to set for half an hour post-baking. It’s so easy to make, and so sunny-yellow, I can imagine using it as the base for any savory tart (I bet this roasted eggplant tomato tart would be superb), or even something sweet, with berries, perhaps. The custard bakes up silky smooth and a little bit tangy. And the queen of spring reigns on top, the spears roasting and condensing in the heat of the oven.

It’s a tart that I wouldn’t hesitate serving to Deborah Madison herself (assuming she doesn’t get a restraining order first).

The Queen of Spring:

Asparagus, Leek and Green Garlic Soup
Spring Tabbouleh with Harissa and Grilled Halloumi
Crustless Asparagus Goat Cheese Skillet Quiche

One year ago:

Gluten-Free Espresso Cheesecake Brownies

Two years ago:

Fava Bean and Radish Crostini

Three years ago:

Creamy Sesame Soba Noodle Salad
Rosemary Pine Nut Biscotti

Asparagus and Shiitake Mushroom Tart with Polenta Crust

I used the smaller amount of asparagus here, and thought a little extra wouldn’t hurt. Save the trimmed ends for another use, or cut them into 1/2″ pieces and roast them with the shiitakes, adding them to the tart filling. The truffle salt is optional, but it does add a lovely, magical quality to the tart. (We’ve been enjoying it over pasta and popcorn, too!) Sometimes I add a tablespoon or two of chopped tarragon or chives on top of the mushrooms.

Makes 6-8 light servings

For the crust:
2 1/2 cups water
1/2 teaspoon fine sea salt
1 cup polenta (or yellow corn grits)
1 tablespoon unsalted butter, plus more for greasing the pan
1/2 cup (1 1/2 ounces) grated parmesan
1/4 teaspoon freshly ground black pepper
1 large egg

The vegetables:
6 ounces shiitake mushrooms
1 tablespoon olive oil, plus another tablespoon for the asparagus
a few big pinches truffle salt (or sea salt)
8 – 12 ounces asparagus spears

The custard and cheese:
1/2 cup whole milk Greek yogurt
1 large egg
1/2 cup whole milk
1/4 teaspoon truffle salt or fine sea salt
1/4 teaspoon freshly ground black pepper
1/2 cup (1 1/2 ounces) grated parmesan

3 ounces crumbled feta cheese

Make the crust:
Position a rack in the lower third of the oven and preheat to 400ºF. Grease a 10″ tart pan (or 9″ pie or springform pan) with butter and place it on a rimmed baking sheet. Set aside.

Bring the water and salt to a boil. Add the polenta in a steady stream, whisking constantly. Lower the heat to medium-low and cook, stirring constantly, until the polenta is very thick, 10 minutes. Off the heat, stir in the butter, parmesan and pepper, then stir in the egg. Scrape the polenta into the greased pan, and spread it with the spatula to cool a bit. When cool enough to handle, use damp fingers to form a 1/2″ thick lip around the edge.

Bake the crust until the surface is dry and pale golden, 20-30 minutes.

Prepare the vegetables:
Rinse the mushrooms quickly, dry them on a kitchen towel, and trim off the ends of the stems. Cut the mushrooms into 1/4″ slices and spread on a smallish baking sheet in a single layer. Drizzle with a tablespoon of olive oil and sprinkle with the truffle salt. Toss to coat, then bake them until golden and collapsed, 10-20 minutes. Lower the oven temperature to 375ºF.

Rinse the asparagus spears well. Snap off the woody ends and discard; they will naturally break off in the right place. Trim the head ends into 3 1/2″ lengths (or 3″ lengths is using a 9″ pan). (Optionally, cut the remaining end pieces into 1/2″ lengths and roast them with the mushrooms.)

Make the custard:
Whisk together the yogurt and egg until smooth. Add the milk, salt and pepper, and whisk until combined.

Assemble and bake the tart:
Sprinkle the parmesan over the bottom of the parbaked crust. Top with the crumbled feta, then the mushrooms (and optional asparagus ends.) Pour the custard over, then arrange the asparagus spears in a circle with the heads pointing in. Drizzle the asparagus with the remaining tablespoon of olive oil, and sprinkle with another pinch of truffle or sea salt.

Bake the tart until the custard is set and a knife inserted near the center comes out clean, about 40 minutes. Let the tart cool for at least 30 minutes and up to an hour; this will firm up the bottom of the crust, ensuring clean slices. I like the tart best slightly warm, but not hot.

Store leftovers in the refrigerator for up to three days, and reheat in an oven or toaster oven before serving.

15 thoughts on “Asparagus and Shiitake Mushroom Tart with Polenta Crust”

  1. Teeehee! You are SO very welcome. (: Bwaaahaha. JUSTICE!!!!

    Umm…omg…polenta crust — WHAT. I love a good buttery pie crust, but I have a severe infatuation with polenta (which you would never be able to tell from my blog). I remember hearing so many people in the northeast recoil in horror at the mention of grits when I was little. When my family visited Florida when I was around 10ish, I decided to try some when we were out for breakfast (probably at the insistence of someone that was not me, because I was never known for being adventurous when it came to food in my younger days). They were so buttery and salty and awesome, with that great, well, gritty texture — instantly obsessed. I can imagine how great the texture of the crust is against the custard too. Oh man, polenta crust. It's happening, ASAP.

    And I know you mentioned bad experiences with other chefs in our emails, but that "Steve" story is just terrible. Gah! (Was that DL? It would make me so sad, but I could definitely picture it….siiiiigh.)

    1. Yeah, justice! "Steve" is definitely NOT DL!! (But good guess!) Though I did go to a book signing with DL once and he looked rather miserable (not that I would blame him). When I got to the front of a very long line after about an hour of shuffling along, he talked to someone else while he signed my book. I thanked him and left. This was disappointing as I used to refer to him as "my future gay Parisian husband," but I couldn't blame him at all as he had a ton of books to get through! (Whereas "Steve's" behavior was both uncalled for and unforgivable.)

      I was worried that the DM book signing experience would be the same, but instead she seemed delighted to be there. Granted, this was a private brunch event rather than a public bookstore signing, but she took the time to chat with me, acted delighted rather than freaked out when I handed her a bag containing a bottle of bergamot bitters and a jar of rum-kissed coconut granola, and scrawled "Especially for Alanna" on the front page of the book. It was love at first sign. :) Such a relief!

      I lovelovelove grits, too! I wish they were on more menus around here. I can't figure out why people would recoil at such a silky vehicle for cheese, salt and butter, but, as my mom says, they're entitled to their own opinion even if it's wrong. ;)

  2. I agree with carey: polenta crust!

    I hate it when people rave about a recipe and when you read their review it's all substitutions so here's my disclaimer: I had no fresh shiitake so used dried (rehydrated), no asparagus but fresh from the garden broccoli rabe, no truffle salt but truffle oil.

    The crust and custard were made as written, delicious – and yes the vibrant yellow is beautiful. The only problem was the polenta was delicious on its own and not all of it made it into the pan ;)

    Alanna, there seems to be some Parmesan missing in the filling – you mentioned it in "Assemble and bake the tart" – was I supposed to use some of the 1/2 cup I added to the crust?

    1. Hi Katherine! Yikes, this is why the pros hire recipe testers – thanks for being mine! ;) I added the half cup of parmesan that I sprinkle over the crust to the ingredient list – so sorry about that!

      I know what you mean about rave recipes with tons of substitutions, but I also think it's a testament to the durability of a recipe when it can handle lots of subs. (Yours sound great!) On the other hand, people who COMPLAIN about a recipe when they have used all kinds of substitutions – there is no excuse for that. :)

    2. Well I made it without the Parmesan over the bottom of the crust – just the feta – but no loss. Still plenty rich and delicious.

      I can't believe this is the only mushroom recipe you've posted! But don't post one now – wait until fall when I'm ready :-)

  3. I just made this (with just one substitution ;-) brown button mushrooms for shitake) and it was delicious! Not to mention such a pretty looking dish. I've been fascinated with polenta but have never found a good recipe for it until now, so thanks!!

  4. I made this tart, and thought it was phenomenal — what a great crust solution for gluten-free quiche lovers! So then I followed up on your suggestion and tried the polenta crust with your eggplant-tomato tart recipe. That was phenomenal, too. My brunch guests say thank you! — E.S.

  5. Hi! I am planning on making this tart (looks and sounds absolutely perfect!), but I was wondering if you had any suggestions for what to serve it with. I was thinking of having this as a side and have something else (vegetarian) for a main. Thanks in advance for any direction!

    1. Hi Lydia, I hope you love the tart! The tart is fairly rich so I'd serve it with something light and fresh. I bet it would go nicely with this caprese gazpacho (, or this strawberry caprese salad ( or this panzanella ( Let me know what you end up doing! -A

  6. I’m wondering if you recommend any other vegetables to use other than asparagus since it’s not in season during the winter. Thoughts?

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