Preheat oven to 425º. Press crust into a 9 inch quiche pan, prick crust and bake until lightly browned, about 10 minutes.
In a large bowl whisk together the eggs, milk, salt and pepper. Sprinkle the bacon, sausage, ham, green onions, and cheese evenly on top of precooked crust. Pour the egg mixture on top.
Bake for 20 minutes until the center is set and a toothpick comes out clean. Allow to cool slightly before serving.
Notes
Season the filling well: Add a pinch of salt, pepper, and spices like paprika or garlic powder to enhance the flavors of the meats and cheese.Avoid overbaking: Bake just until the center is set but slightly jiggly—it will continue cooking as it cools.