Spray an 8-inch square baking dish with cooking spray. Spread ½ of the enchilada sauce in the bottom of the dish.
In a small bowl, combine beans, corn, onion, broccoli, ½ cup of the cheese, and salsa.
Top each tortilla with about ¼ of the bean mixture. Roll up and place seam-side down in the baking dish. Pour the rest of the enchilada sauce over the top and sprinkle with remaining ½ cup of cheese.
Cover tightly with foil and freeze for up to 3 months.
To cook: Thaw enchiladas in the refrigerator overnight. Allow dish to sit on the counter at room temp for about 30 minutes before baking.
Bake in a 400-degree oven for about 15 minutes, or until heated through.
If the enchiladas are still partially frozen, you might need to increase the baking time. You can keep the dish covered with foil to prevent the cheese from getting too crispy on top while they cook for a longer amount of time.