How to Make It
Preheat oven to 350°.
Weigh or lightly spoon self-rising flour and 1/2 cup white whole-wheat flour into dry measuring cups; level with a knife. Place flours in a medium bowl. Cut in butter with a pastry blender or 2 knives until mixture resembles coarse meal. Add buttermilk, 2 teaspoons thyme, and 1/4 teaspoon salt; toss with a fork until moist. Drop dough by tablespoonfuls onto a foil-lined baking sheet coated with cooking spray (about 24 total). Bake at 350° for 25 minutes or until browned. Cool.
Heat a Dutch oven over medium-high heat. Add 1 1/2 tablespoons oil to pan; swirl. Add half of turkey; cook 3 minutes. Remove cooked turkey from pan. Repeat with remaining turkey.
Add remaining 1 1/2 tablespoons oil to pan. Add remaining 2 tablespoons thyme, 1/2 teaspoon salt, onion, and next 5 ingredients (through mushrooms); cook 5 minutes. Combine remaining 1/2 cup white whole-wheat flour and stock in a bowl. Add stock mixture to pan; bring to a boil. Add potato; cook 5 minutes. Stir in remaining 1/2 teaspoon salt and turkey; simmer 15 to 20 minutes or until stew is thickened. Top with thyme sprigs, if desired, and serve with biscuits, or follow freezing instructions.
HOW-TO Freeze: Cool stew and biscuits completely. Freeze separately in zip-top plastic freezer bags. Thaw: Microwave stew in bag at MEDIUM (50% power) for 4 minutes or until pliable. Reheat: Pour stew into a Dutch oven; simmer 20 minutes. Bake biscuits at 350° for 25 minutes.