Savory Pie Crust:
1 3/4 cups all-purpose flour
1 teaspoon salt
1/4 teaspoon pepper
1 stick plus 2 tablespoons cold unsalted butter, cut into cubes
1/2 cup grated gruyere
1/3 cup ice water
In a food processor, pulse the flour with 1 teaspoon of salt and 1/4 teaspoon of pepper. Add the butter, gruyere and pulse until the mixture resembles coarse meal, with some pea-size pieces of butter still visible. Sprinkle the ice water over the mixture and pulse until the dough just starts to come together; you should still see small pieces of butter. Scrape the dough out onto a work surface, gather up any crumbs and pat the dough into an 8-inch square. Wrap in plastic and refrigerate until well-chilled, about 1 hour or for up to 2 days.
2 tablespoons extra-virgin olive oil, plus more for drizzling
2 medium-size onions, thinly sliced
1 teaspoon salt
1/4 cup heavy cream
spring vegetables: ¼ pound asparagus (halved), ¼ pound fingerling potatoes (boiled and sliced), ¼ spring onions, ½ cup peas
4 ounces feta cheese, crumbled
edible flowers, to garnish
Heat the olive oil in a large, heavy sauté pan or skillet over medium-high heat. When it is hot, add the onions, season with salt, and cook until they release some liquid and begin to develop a few dark spots, about 3-5 minutes. Reduce the heat and continue to cook until the onions are soft, 20-30 minutes. Allow the onions to cool.
Whisk the cream and egg together and fold in the cool onion mixture. Top with feta cheese.
On a lightly floured surface, roll the dough into a circle, 1/4-inch thick. Transfer to the refrigerator to chill for 30 minutes. Preheat the oven to 375 degrees. Spread the filling over the pastry, leaving a 2-inch border. Add seasonal ingredients of your choice to onto the onion base, drizzle with oil, season with salt and pepper. Fold the border up over the filling, allowing the dough to fold over on itself. Transfer to a prepared sheet pan. Bake until the filling is bubbly and the crust is deep golden brown, 40 to 45 minutes.
Garnish galettes with edible flowers.