1. Preheat oven to 425°F. Prick pie crusts with fork six or seven times and bake crusts for 10 minutes.
2. Sauté bacon over medium heat until crisp, about 10 minutes. Drain on paper towels.
3. Cut asparagus into 1/2 inch pieces, discarding the tough ends.
4. Whisk together milk, cream, sour cream, eggs, salt and pepper. Fold the asparagus, bacon, green onions, and Swiss cheese into the mixture. Pour mixture into prebaked crusts and top evenly with the cheddar cheese.
5. Bake 10 minutes at 425°F. Lower heat to 350°F and continue baking for 20 minutes or until center is set.
6. Allow to cool 10 minutes before serving.