Vegetarian Potluck Casserole

Ingredients

• 2.00 cups cooked brown rice
• 1.00 tablespoon olive oil
• 1.00 cup chopped onion
• 1.00 cup chopped bell pepper
• 1.00 cup chopped mushrooms
• 1.00 cup chopped zucchini
• 1.00 cup chopped carrots
• 1.00 cup frozen corn
• 1.00 cup canned black beans, drained and rinsed
• 1.00 cup marinara sauce
• 1.00 cup shredded mozzarella cheese
• 1.00 cup grated parmesan cheese