Thaw shrimp, if frozen. Preheat oven to 350 degrees F. Grease a 3-quart rectangular baking dish; set aside. In a large skillet cook chile peppers, onion, and garlic in hot butter about 5 minutes or until onion is tender. Add cream cheese, stirring until smooth. Stir in shrimp and tomatoes. Remove from heat. Stir in 1 cup of the Monterey Jack cheese and 1 cup of the cheddar cheese. Transfer mixture to prepared baking dish.
In a medium bowl combine flour, baking powder, baking soda, and salt. In a small bowl combine egg, milk, and oil. Add egg mixture to flour mixture, stirring until smooth. Pour over shrimp mixture. Sprinkle with the remaining 1 cup Monterey Jack cheese and the remaining 1 cup cheddar cheese.
Bake, uncovered, for 35 to 40 minutes or until golden brown and set in the center.