Fit 1 piecrust into the bottom and up the sides of a 2-quart baking dish.
Bake at 400° for 9 minutes or until lightly browned.
Melt butter in a large saucepan over medium-high heat; add sausage, onion, and flour, and sauté 5 minutes. Whisk in milk; cook, whisking constantly, 5 minutes or until thickened.
Remove from heat; stir in vegetables, next 3 ingredients, and, if desired, thyme. Pour into prepared piecrust.
Unfold remaining piecrust, and roll to press out fold lines; place piecrust over turkey mixture, trimming to fit. Crimp and cut slits on top for steam to escape.
Bake at 400° for 20 minutes or until golden.
Note: For testing purposes only, we used McKenzie's Vegetable Gumbo Mixture.