We’re turning all our Thanksgiving favorites into pies this year. Welcome to Piesgiving 2021. Bring your appetite.
At Thanksgiving, we play fast and loose with the concept of vegetables. Sweet potatoes are full of vitamins, minerals, and dietary fiber, and we gleefully cover them in marshmallows and corn syrup. Green beans could be steamed or sauteed, but don’t they feel more festive when mixed with canned cream soup and fried onions? And then there’s the pearl onion, a tragically underrated vegetable that’s best served in a rich sauce of butter and cream.
I encourage you all to go as hard as you can with vegetables on Thanksgiving. Drench them in butter, saturate them in syrup, pour in so much heavy cream that it begins to replace all the water in your body.
This year, my green bean “casserole” will be contained in a buttery puff pastry shell, my cranberry sauce will be nestled into a gingersnap cookie crust, and my onions will be caramelized, creamed, swaddled in my signature mega-flaky pie crust, and baked into a truly life-changing crostata.
No one can resist the rustic, cheesy charms of this rich dish. And since the beauty of a crostata is that it’s supposed to be a little bit messy, it doesn’t matter if this tears, leaks, or comes out looking lopsided. Besides, if it looks too pretty, you might feel bad about going hog wild on it, and I assure you, a’hog wild you shall go. If you can’t do that to your vegetables on Thanksgiving, then when?
- 1 batch mega-flaky pie crust
- 2 Tbsp. butter
- 3 bags frozen pearl onions
- 1 Tbsp. flour
- 1½ cups half and half
- 2 Tbsp. Dijon mustard
- 1/4 tsp. fresh grated nutmeg
- Kosher salt
- Freshly cracked pepper
- 4-5 sprigs fresh thyme, stripped from the stems
- 4 oz. firm grated cheese (Parmesan, Gruyere, and Piave are all excellent choices)
First, make the mega-flaky pie crust by following the recipe here.
Melt the butter in a cast iron skillet over high heat, then add the frozen onions with a big pinch of kosher salt. Cook for 10 minutes or so, stirring occasionally, until the onions turn a light shade of brown.
Stir in the flour, cook for 15-30 seconds until it’s no longer visible, then add the half-and-half and turn off the heat. Use a wooden spoon to help scrape up the brown bits at the bottom of the pan, then stir in the Dijon mustard, nutmeg, a few cracks of black pepper, a pinch of thyme leaves (don’t use them all!), and half the grated cheese.
Now here’s the important part: let the onion mixture cool just a little, then taste it. The seasoning makes or breaks this crostata, so add more salt, pepper, nutmeg, thyme, and cheese as you see fit. Keep tasting and tweaking until you get it just right, then set aside to cool to room temperature.
Preheat the oven to 400 degrees Fahrenheit. Cut a piece of parchment paper large enough to fit a sheet pan and lay it out on your counter. Plop your pie dough in the middle and start rolling out into a rough circle about 1/4" thick and at least 18" wide. (It’s totally fine if it isn’t perfect; crostatas are supposed to be “rustic.”)
Dock the dough all over at roughly 2-inch intervals with a fork, then squish together any scraggly broken edges and toss any errant dough bits into the center. (No reason to throw away perfectly good scraps.) Brush the crostata all over with egg wash, then add the onion mixture to the center, spreading it out into a circle, stopping at least 4" away from the perimeter of the pie dough. Fold the edges of the dough up and in, sculpting it like Play-Doh as needed to form its shape.
Slide the parchment onto a sheet pan, brush the crostata with egg wash, and grate on some more cheese, if desired. Bake for 50-60 minutes, keeping an eye on it toward the end, until the dough is crisp and golden brown. Let the crostata cool for at least 10 minutes before serving hot, warm, or at room temperature.
TIP: You can make the onion filling up to four days ahead of time. Store in an airtight container in the fridge; no need to warm or bring to room temperature before assembling the crostata.