Bring 2.5 cups of water to boil. Add 1 cup of rice. Return to boil. Stir and reduce heat to medium low. Cover and cook for 20 minutes.
Chop onion and put in skillet. Add 3/4 lb ground beef. Brown the beef with the onion.
Return meat/onion mixture to skillet. Set heat to medium-low. Add 1 can of diced tomatoes. Cook for about 5-7 minutes.
Once the rice has finished cooking, add it to meat/onion/tomato mixture in the skillet. Mix well.
Shred 4-6 oz of cheese (any type). Sprinkle over the top of the rice/meat mixture in the skillet. Set to cook on low for about 5 minutes or until cheese is melted.