Directions

1. Heat oven to 400 degrees F with one rack at upper-middle level and one rack at lower-middle level. Wash the whole squash and place on a parchment-lined baking sheet. Place in oven on upper rack. Roast squash whole until paring knife can be inserted easily into flesh, about 30 minutes. Remove squash from oven and when cool enough to handle, place squash on cutting board and cut in half. Scoop out and discard seeds. Slice squash into thin wedges, about 1/4-inch thick. Place squash slices on baking sheet, brush both sides of slices with olive oil, and sprinkle with salt and pepper. Return pan to oven and bake until squash is fork-tender, about 10 minutes longer. Remove pan from oven and raise oven temperature to 425 degrees F.
2. Meanwhile, in a small bowl, mix together shallots, sage, ricotta, 1/2 cup Parmesan cheese, 1/2 teaspoon salt and 1/4 teaspoon black pepper.
3. Roll pie crust into a 12-inch circle. Transfer to a flat cookie sheet or pizza pan. Spread filling on crust, leaving a 1 1/2 -inch border. Arrange roasted squash slices in single layer on top of filling. Fold edges of crust inward over filling and brush pastry edges with beaten egg. Sprinkle galette (including crust) with remaining Parmesan cheese. Bake on lower-middle rack in a 425 degrees F oven until crust is cooked and golden, 20-25 minutes. Remove pan from oven and let cool slightly before slicing to serve.