Preheat oven to 400°F.
In a medium skillet, melt butter over medium heat. Add onions and mushrooms and cook until soft, about 5 minutes. Add garlic and cook for 1 minute. Add flour and stir until vegetables are coated.
Add broth slowly while whisking constantly. Mixture will be lumpy but should become smooth as you whisk. Once all broth is incorporated, whisk in the milk.
Stir in thyme, salt, and pepper. Bring to a boil and cook for a few minutes until thickened. Taste and adjust seasoning if needed. Remove from heat and stir in cooked turkey.
Add mixture to a 9 inch pie plate and top with rolled out pie crust. Tuck and crimp pie crust edges, cut a few slits for vents, and brush with egg wash, if using.
Bake until crust is golden and filling is bubbling, about 30-35 minutes. Serve immediately, store any leftovers in the refrigerator.
- Vegetable substitutions: Add up to 1-1½ cup additional vegetables like carrots, peas, corn, green beans or potatoes. Or reduce mushrooms to 1 cup and use 1½-2 cups desired veggies.
- Pie crust: This is a great way to use up a leftover pie crust! You can also use store-bought or even frozen puff pastry. If you use my pie crust recipe, you'll end up with 2 crusts. Wrap one well with plastic wrap and store in the freezer for up to 3 months, for another use.
- Save a dish: You can make this whole dish in an ovenproof skillet (I like to use cast iron), prepping the filling on the stove top and then baking it in the oven.
Calories: 395kcal, Carbohydrates: 19g, Protein: 47g, Fat: 15g, Saturated Fat: 6g, Cholesterol: 140mg, Sodium: 913mg, Potassium: 769mg, Fiber: 2g, Sugar: 3g, Vitamin A: 249IU, Vitamin C: 5mg, Calcium: 77mg, Iron: 2mg