Heat a medium-sized skillet over medium-high heat. Add 1 pound lean ground beef, ½ cup chopped onion, 1 diced green bell pepper, 1 diced red bell pepper, and 3 minced garlic cloves.
Cook, stirring occasionally, until the ground beef is no longer pink and the vegetables are tender, about 4–5 minutes.
Add 1 teaspoon chili powder, ½ teaspoon paprika, ½ teaspoon salt, ¼ teaspoon pepper, 1 (16-ounce) can tomato sauce, and 1⅓ cups instant rice. Stir to combine.
Bring the mixture to a boil, then cover the skillet, reduce the heat to low, and simmer for 5–7 minutes or until the instant rice is tender.
Remove the lid, sprinkle 2 cups shredded cheddar cheese over the skillet, and stir until the cheese has melted and the mixture is evenly combined.
Garnish with chopped cilantro and serve.