Preheat oven to 425°F. Let pie crust stand at room temperature according to package directions. Line a 9-inch pie plate with pie crust. Crimp edge as desired. Line unpricked pie crust with a double thickness of foil. Bake for 8 minutes. Remove foil. Bake for 4 to 5 minutes more or until piecrust is set and dry. Remove from oven. Reduce oven temperature to 350°F.
Coat an unheated medium skillet with cooking spray. Heat over medium heat. Add chicken to skillet. Cook and stir for 6 to 8 minutes or until chicken is done and no longer pink. Remove chicken from skillet. Return skillet to heat. Add spinach and cook over medium heat for 1 to 2 minutes or until wilted, turning frequently.
In a large bowl whisk together the eggs, chicken, spinach, cheese, milk, roasted peppers, thyme, salt, and pepper. Pour egg mixture into baked pie crust.
Bake for 40 minutes. If necessary to prevent overbrowning, cover edge of quiche with foil. Bake for 5 to 10 minutes more or until a knife inserted near center comes out clean. Let stand on a wire rack for 10 minutes before serving. Cut into wedges and place one wedge of each of four serving plates (see Tip).
Tip: Cover leftover quiche with plastic wrap and refrigerate for up to 24 hours. To reheat, preheat oven to 350°F. Remove plastic wrap from quiche. Cover loosely with foil. Bake about 40 minutes or until heated through (165°F).
Serve with Baby Mixed Green Salad and Citrus-Infused Strawberries (see associated recipes).