Grease a 9x13 baking dish with cooking spray and set aside.
Heat olive oil in skillet and add sausage; cook for 6 minutes.
Add peppers and onions; season with salt and pepper and continue to cook for 3 to 4 minutes, or until peppers are slightly tender.
Remove from heat and stir in chilies.
Spoon about 1/3 cup sausage mixture down the center of each flour tortilla and 2 tablespoons of the cheese.
Roll up and place the filled tortillas, seam side down, in the baking dish. Set aside.
In the bowl of your electric mixer, combine eggs, heavy cream, milk, flour and chili powder; mix on low for 1 minute, or until well combined.
Pour the egg mixture over the tortillas.
Cover with foil and refrigerate overnight.
Preheat oven to 350F.
Bake the enchiladas, covered, for 25 minutes.
Uncover and continue to bake for 25 minutes.
Sprinkle 1/2-cup cheese over the top and continue to bake for 3 more minutes, or until cheese is melted.
Remove from oven and let stand 15 minutes.
Optionally, garnish with sour cream, green onions, tomatoes, avocado, green peppers and cilantro or parsley.
Cut and Serve.