Buttery Pastry Shell
2 cups (250 grams) all-purpose flour, plus more for dusting
1 teaspoon kosher salt
1 cup (2 sicks or 225 grams) very cold unsalted butter, cut into a small dice
1/4 cup (60 ml) water, ice cold
Neutral oil, for brushing springform

Filling
1 tablespoon (15 ml) olive or vegetable oil
2 pounds (905 grams) mushrooms (see Note up top for suggestions)
Salt and freshly ground black pepper
1 tablespoon (15 grams) unsalted butter
2 shallots, minced (I used 4 small because I’m a rebel)
1 tablespoon fresh thyme, minced (use 1 teaspoon only if dried/jarred)
3/4 cup (2 1/2 ounces or 70 grams) Comte, Emmantel or Gruyere, grated
2 cups (475 ml) milk
2 cup (475 ml) heavy cream
6 large eggs, lightly beaten
Freshly grated nutmeg (optional)