Preheat the oven to 375°F (190°C).
Place the refrigerated pie crust into a 9-inch pie dish, pressing it firmly against the bottom and sides. Trim any excess dough and crimp the edges as desired.
In a medium skillet, heat the olive oil over medium heat. Add the chopped onion and green bell pepper and sauté for 5 minutes until softened. Remove from heat and set aside.
In a large mixing bowl, whisk together the eggs, low-fat milk, salt, black pepper, and garlic powder until well combined.
Stir in the shredded cooked chicken, sautéed onion and bell pepper, shredded cheddar cheese, and grated Parmesan cheese into the egg mixture.
Pour the filling evenly into the prepared pie crust.
Bake in the preheated oven for 35 to 40 minutes, or until the quiche is set and the top is lightly golden. A knife inserted in the center should come out clean.
Remove the quiche from the oven and let it cool for 10 minutes before slicing and serving.