J.W. s Pepper and Mozzarella Casserole

1 (28 ounce) can tomato sauce

1 (6 ounce) can tomato paste

1 (8 ounce) can sliced mushrooms, drained

1 (12 ounce) package shredded mozzarella cheese

¾ teaspoon crushed red pepper flakes

2 tablespoons olive oil

3 green bell peppers, thinly sliced

3 red bell peppers, thinly sliced

3 onions, thinly sliced

3 cloves garlic, minced

Preheat an oven to 350 degrees F (175 degrees C). Mix the tomato sauce, tomato paste, mushrooms, mozzarella cheese, and red pepper flakes together in a bowl.

Heat the vegetable oil in a skillet over medium heat. Stir in the green and red bell peppers, garlic, and onion; cook and stir until the onion has softened and turned translucent, about 5 minutes. Drain and reserve the liquid from the vegetables; set aside.

Spread about 1/3 of the tomato sauce mixture into the bottom of a casserole dish. Layer 1/2 of the vegetables on top, then repeat the layers, topping with the remaining 1/3 of sauce. Drizzle the reserved liquid from the vegetables on top.

Bake in the preheated oven until the cheese is melted and the sauce is bubbly, about 45 minutes.