2 sheets store-bought pastry dough, rolled to 15 inches by 10 inches
2 tablespoons olive oil
8 slices (3 ounces) prosciutto, finely chopped
1 (8 ounces) Vidalia onion
8 ounces morel mushrooms, cleaned and trimmed
18 eggs, whisked
¼ cup heavy cream
1 cup watercress, loosely packed
Kosher salt and freshly ground black pepper, to taste
2 tablespoons chives, thinly sliced, for garnish
Aleppo pepper, for garnish
Flaked salt, for garnish
½ cup crème fraîche, for serving
1. Blind-bake the crust: Preheat the oven to 400º. Place one piece of rolled-out dough on one side of a sheet pan and one on the other side of the pan. Press down along the center where the two sheets meet so they come together. Use your hands to form a rim with the dough that goes up the lip of the sheet pan, forming your crust. Using a fork, prick the surface of the dough to keep it from puffing up. Place a piece of parchment paper over the dough and then another sheet pan on top to weigh it down. Bake the dough for 20 minutes, then remove the sheet pan and parchment paper, and bake the dough again until golden brown, 5 minutes. Allow the dough to completely cool.
2. While the dough is baking, make your filling: In a large sauté pan, heat the oil over medium-high heat. Add the chopped prosciutto and cook until the fat is rendered and the bits are golden brown and crispy, 7 minutes. Using a slotted spoon, transfer the prosciutto to a large bowl and allow to cool. Place the same pan over medium heat, add the onions and cook until they begin to soften and take on some color, 10 minutes. Add the morels and cook for 5 more minutes. Transfer the onions and mushrooms to the same bowl as the cooked prosciutto and allow to completely cool.
3. While the prosciutto mixture is cooling, continue making the rest of the filling. In a medium bowl, whisk together the eggs and heavy cream so that until they are completely incorporated. Add the egg mixture and the watercress into the bowl with the cooled prosciutto, then mix and season with salt and pepper.
4. Pour the filling into the cooled quiche crust and bake for 10 to 15 minutes until the filling sets, but the eggs are not glossy or overcooked. Allow the quiche to cool slightly for 5 to 10 minutes. Cut the pieces directly in the pan into 3 columns and 4 rows and garnish with chives, Aleppo pepper and flake salt. Serve immediately with crème fraîche on the side.