Crumble the ground beef into a skillet over medium-high heat add onion. Cook and stir until evenly browned. Drain off grease, and stir in the cream of mushroom soup, tomatoes,chilies, and uncooked rice. Cover, and simmer over low heat, stirring occasionally, until rice is cooked, about 20 minutes.
When the rice is done cooking,Cover with a layer of cheese till melted.