Preheat oven to 450°F (230°C). Divide tomatoes, bacon and green onions evenly between the two frozen pie shells.
Whisk eggs and milk together; season well with salt and pepper. Pour evenly over the 2 quiches. Sprinkle cheese crumbles evenly over each quiche.
Bake 10 min. Reduce oven temperature to 350°F (180°C) and continue baking until quiches have set, about 30 min. Let cool slightly and serve with a side salad for a light meal.