1. In a food processor, combine the flour and salt. Add the cold butter and pulse until the mixture resembles coarse crumbs. Add the ice water and pulse just until the dough starts to come together.

2. Turn the dough out onto a lightly floured surface and gather it into a disc. Wrap in plastic wrap and refrigerate for at least 30 minutes.

3. In a large skillet, cook the Italian sausage over medium heat until browned and crumbled, about 5-7 minutes. Drain any excess fat.

4. Add the onion and garlic to the skillet and cook until softened, about 3-4 minutes.

5. Stir in the tomato sauce, oregano, basil, and red pepper flakes (if using). Simmer for 5 minutes, then remove from heat and let cool slightly.

6. Preheat the oven to 400°F.

7. On a lightly floured surface, roll the dough out to 1/8-inch thickness. Use a 4-inch round cookie cutter or biscuit cutter to cut out 8 circles.

8. Divide the sausage mixture evenly among 4 individual oven-safe ramekins or a 9-inch pie dish. Top each with a dough circle, pressing the edges to seal.

9. Brush the top of the dough with the egg wash.

10. Bake for 20-25 minutes, or until the crust is golden brown.

11. Let cool for 5 minutes before serving.