Turkey Potpie With Cheddar Biscuit Crust

• Carcass and skin from a 12- to 14-pound roast turkey
• 10 cups water
• 1 medium onion, coarsely chopped
• 2 large carrots, cut into 1/2-inch pieces
• 2 celery ribs, cut into 1/2-inch pieces
• 1 large parsnip (peeled), cored and cut into 1/2-inch pieces
• 1 teaspoon chopped thyme
• 3 tablespoons unsalted butter
• 1/2 pound mushrooms, trimmed and quartered
• 1/4 cup all-purpose flour
• 4 cups roast turkey meat, cut into 1/2-inch pieces
• 1 (10-ounce) package frozen baby peas, thawed
• 2 cups all-purpose flour
• 2 teaspoons baking powder
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• 1/2 teaspoon black pepper
• 1 cup coarsely grated extra-sharp Cheddar
• 1/4 cup
• 3/4 stick cold unsalted butter, cut into 1/2-inch pieces
• 1 1/4 cups well-shaken buttermilk

1. Separate parts of carcass and put, along with skin, in an 8-quart pot. Cover bones with water and simmer until liquid is reduced by one third, about 1 1/2 hours. Strain through a fine-mesh sieve into a large bowl. Set aside 3 1/2 cups stock (reserve remainder for another use).
2. Cook onion, carrots, celery, parsnip, and thyme in butter with 1/2 teaspoon salt and 1/4 teaspoon pepper in a 12-inch-wide shallow pot (3- to 4-quart), covered, over medium heat, stirring occasionally, until vegetables are almost tender, 10 to 12 minutes. Add mushrooms and cook, uncovered, stirring, until tender, 5 to 7 minutes.
3. Sprinkle with flour and cook, stirring constantly, 2 minutes. Stir in stock (3 1/2 cups), scraping up any brown bits, and bring to a boil, stirring, then simmer until slightly thickened, about 3 minutes. Stir in turkey, peas, and salt and pepper to taste. Reheat over low heat just before topping with biscuit crust.
4. Preheat oven to 400u0b0F with rack in middle.
5. Sift together flour, baking powder, baking soda, salt, and pepper into a medium bowl. Add cheeses and toss to coat. Blend in butter with a pastry blender or your fingertips until mixture resembles coarse meal. Add buttermilk and stir just until a dough forms. Drop biscuit dough onto filling in 8 large mounds, leaving spaces between biscuits.
6. Bake until biscuits are puffed and golden brown and filling is bubbling, 35 to 40 minutes. Let stand 10 minutes before serving.

carcass, water, onion, carrots, celery, parsnip, thyme, unsalted butter, mushrooms, allpurpose, turkey meat, baby peas, flour, baking powder, baking soda, salt, black pepper, cheddar, cold unsalted butter, wellshaken buttermilk

Taken from www.epicurious.com/recipes/food/views/turkey-potpie-with-cheddar-biscuit-crust-240566 (may not work)