Beef and Rice Casserole

Rice (cooked, 4 cups)

Olive oil (2 tbsp)

Onion (diced, 1/4 cup)

Garlic (minced, 2 tbsp)

Ground beef (1 lb)

Corn (1 can)

Frozen broccoli (2 cups)

Cream of mushroom soup (2 cans)

Colby jack cheese (shredded, 2 cups)