1. Preheat oven to 400°. Toss squash with olive oil and 1 tablespoon melted butter; add sea salt and pepper. Spread evenly on a lightly greased foil-lined rimmed baking sheet. Bake at 400° for 30 minutes or until tender and golden brown, stirring once.
2. Add remaining 2 tablespoons melted butter to a large nonstick skillet, and cook shallot and mushrooms over medium heat, stirring frequently, about 10 to 12 minutes or until most of liquid is absorbed. Add flour, and cook, stirring frequently, about 3 to 4 minutes or until brown. Slowly whisk in broth, and bring to a low boil, stirring constantly.
3. Stir in turkey, sage, and additional sea salt and pepper. Cook 5 minutes or until thick and creamy. Remove from heat; let cool slightly. Stir in baked squash and half-and-half.
4. Roll puff pastry on a lightly floured surface, and cut 6 rounds slightly larger than the top of a 10-ounce custard cup. Fill 6 lightly greased cups with turkey mixture, and place pastry over dishes, allowing any excess to drape over the side. Brush with egg wash, and chill at least 1 hour.
5. Preheat oven to 350°. Cut several slits into top of pies, and place on baking sheets. Garnish, if desired, and brush with egg wash.
6. Bake at 350° for 20 to 25 minutes or until pastry has puffed and is golden brown.