2 tablespoons olive oil
1 (2 ounce) can Italian-style diced tomatoes with green chiles
1 (4 ounce) can diced green chiles
1 medium onion, chopped
1 1/2 cups shredded Cheddar cheese
1 cup shredded mozzarella cheese
1 cup shredded Monterey Jack cheese
Preheat oven to 350 degrees F (175 degrees C). Season with salt and pepper.
In a large saucepan over medium heat, heat oil and add diced tomatoes with green chiles, diced green chiles, onion, cheese, mozzarella cheese, and Monterey Jack cheese. Mix together well.
Pour mixture into a 9x13 inch baking dish. Sprinkle with remaining cheese.
Bake in preheated oven for 50 minutes.