Asparagus and Shiitake Mushroom Tart with Polenta Crust
A delicious savory tart made with seasonal asparagus.
Prep Time: 10 minutesminutes
Cook Time: 1 hourhour20 minutesminutes
Total: 1 hourhour30 minutesminutes
Servings: 6to 8 light servings.
Ingredients
For the crust:
2 1/2cupswater
1/2teaspoonfine sea salt
1cuppolenta (or yellow corn grits)
1tablespoonunsalted butter, plus more for greasing the pan
1/2cupgrated parmesan(1 1/2 ounces)
1/4teaspoonfreshly ground black pepper
1large egg
The vegetables:
6ouncesshiitake mushrooms
1tablespoonolive oil, plus another tablespoon for the asparagus
a few big pinches truffle salt (or sea salt)
8 - 12ouncesasparagus spears
The custard and cheese:
1/2cupwhole milk Greek yogurt
1large egg
1/2cupwhole milk
1/4teaspoontruffle salt or fine sea salt
1/4teaspoonfreshly ground black pepper
1/2cupgrated parmesan(1 1/2 ounces)
3ouncescrumbled feta cheese
Instructions
Make the crust:
Position a rack in the lower third of the oven and preheat to 400ºGrease a 10" tart pan (or 9" pie or springform pawith 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.
Notes
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.Nutritional values are based on one of six servings.