In large non-stick skillet, cook beef, bell peppers, and yellow onion over medium-high heat 5 to 7 minutes, stirring frequently, until meat is thoroughly cooked and veggies are tender; drain. Stir in water and taco seasoning mix; heat to boiling. Cook until water is absorbed.
Add the tomatoes and cook until liquid is gone. Sprinkle the cheddar cheese on and let it melt by covering with a lid. Top with desired toppings and eat.
