Position a rack in the center of the oven and preheat to 350ºF (175ºC). Lightly rub the inside of a 9x13-inch (22x33cm) baking pan with olive oil and set aside. Bring a large pot of water well-salted water to a boil.
Prepare the vegetables and pasta:
Break and cut the cauliflower into small florets. Tear the kale off of its stems and discard the stems. When the water is boiling, carefully add the cauliflower and cook until crisp-tender, 2-3 minutes. Scoop out the cauliflower with a slotted spoon, drain well, and place in a very large bowl.
Add the kale, cooking it until it's bright green, 1-2 minutes. Drain well. When cool enough to handle, squeeze out the excess water and chop the kale roughly. Add the cooked kale to the bowl with the cauliflower.
Add the pasta to the pot of boiling water and cook, stirring frequently, until it's just a little firmer than you would want to eat. (It will continue to cook and absorb moisture during the baking process.) Drain the pasta well and add it to the bowl with the vegetables.
Make the sauce:
In a large saucepan (or the now empty pot in which you cooked the veg and pasta), combine the squash puree, vegetable stock, milk, nutmeg, and 1/2 teaspoon salt. Bring to a bare simmer, stirring frequently, then remove from the heat and whisk in the cheddar and ricotta to melt the cheeses. The sauce will seem thin, but it will thicken up during the baking process.
Make the breadcrumb topping:
Heat the 1 tablespoon olive oil in a small skillet over medium heat. Add the bread crumbs and cook, stirring, until crisp, 5 minutes. Scrape into a small bowl, and stir in the Parmesan and a pinch of salt.
Assemble and bake the goodness:
Pour the sauce over the pasta and vegetables, and stir to combine. Scrape the mixture into the greased baking pan and sprinkle with the breadcrumb mixture. Bake the pasta until bubbling and golden on top, 20-30 minutes. Serve hot.
Notes
Adapted from Martha Stewart.I like to make my own squash puree with butternut and/or kabocha squash, both of which have sweeter, more dense flesh than pumpkin. To do this, slice a medium-sized winter squash in half lengthwise with a sharp, large chef's knife. Leave the seeds in for now, and place it cut-side down on an oiled, rimmed baking sheet. Roast at 350ºF until very tender and collapsing slightly. Let cool, scoop out and discard the seeds and strings, then puree the flesh in a food processor. Alternately, you can use a can of pumpkin or butternut squash puree. I used corn and quinoa macaroni here, but penne works well, too. I used sprouted wheat bread for the breadcrumbs, but you can use any bread you like.All ounce measurements are by weight.Nutritional values are based on one of eight servings.