1 can (15 ounces) diced tomatoes
1/4 cup taco seasoning
2 tablespoons minced onion
12 ounces chilies, whole, canned
4 cups (24 ounces) shredded Monterey Jack cheese
2 cups (8 ounces) shredded cheddar cheese
1-1/2 cups milk
1/4 cup flour
1 teaspoon salt
1/2 teaspoon ground white pepper
1/4 teaspoon Spanish Paprika
Combine tomatoes, taco seasoning and minced onions in a small bowl; set aside.
Slice chilies lengthwise and place in a greased 13 x 9-inch baking dish. Spread tomato mixture over chilies; top with cheeses.
Combine milk and flour in a large bowl, beating until smooth with a whisk. Add eggs, salt and ground white pepper; beat until well mixed. Pour over cheese in baking dish. Sprinkle with paprika, if desired.
Bake uncovered at 350°F for 35 to 40 minutes until browned and knife inserted in center comes out clean. Let stand 10 minutes before serving.