Heat oven to 350. Spray 11x7 inch glass dish with cooking spray.

Sprinkle chiles, cheddar and pepper jack cheeses evenly in baking dish. In large bowl, beat milk, Bisquick and eggs with electric mixer on low speed until smooth. Stir in ricotta cheese; spoon evenly over chiles and cheese in baking dish.

Bake uncovered 45 minutes or until knife inserted in center comes out clean. Let stand 10 minutes before cutting.