This galette’s flaky crust stays crisp even when filled with creamy ricotta; be sure to use best-quality cheese, and drain it overnight for superior results. Roasting the mushrooms reduces excess moisture and concentrates their meaty flavor, which pairs perfectly with the fresh thyme, rosemary, and sage.
How to Make It
Stir together flour, salt, and sugar in a medium bowl. Using a pastry cutter, cut in chilled cubed butter until butter resembles small peas. Using a fork, stir in 1/4 cup ice water. Stir in up to 1/4 cup more ice water, 1 tablespoon at a time, just until dough comes together. Shape dough into a disk, and wrap tightly in plastic wrap. Chill at least 2 hours or up to 3 days.
Preheat oven to 400°F. Toss together mushrooms, olive oil, herb sprigs, 1 1/4 teaspoons salt, and 1/4 teaspoon pepper on a rimmed baking sheet; spread into an even layer. Bake in preheated oven until mushrooms are just tender, about 20 minutes. Discard herb sprigs; set mushrooms aside to cool to room temperature, about 15 minutes.
Reduce oven temperature to 325°F. Unwrap dough, and turn dough out onto a lightly floured surface. Roll into a 15-inch circle, about 1/4 inch thick. Stir together drained ricotta, remaining 1/2 teaspoon salt, and remaining 1/4 teaspoon pepper. Spread ricotta mixture on dough, leaving a 2-inch border. Layer roasted mushrooms over ricotta; sprinkle with chopped thyme, rosemary, and sage. Fold edges of dough up over filling, pleating every 2 inches. Lightly brush edges of dough with beaten egg.
Bake at 325°F until crust is golden brown, 50 minutes to 1 hour. Remove from oven, and transfer to a wire rack to cool 10 minutes. Serve warm or at room temperature.