Preheat the oven to 350° F. Spray a 9x13 inch baking dish with non-stick cooking spray and set aside.
Heat a large skillet over medium heat. When the skillet is hot, add the ground beef and diced onion. Cook until the meat is browned and onions are translucent. Drain fat from pan if necessary.
1 lb. ground beef, 1 small yellow onion
Reduce heat to low and add in the taco seasoning and diced tomatoes. Stir to combine and simmer for 5 minutes.
2 tbsp taco seasoning, 14.5 oz. can petite diced tomatoes, drained
Spread the refried beans into the bottom of the prepared baking dish. Place the frozen tater tots on top of the beans in a single layer.
16 oz. can refried beans, 16 oz. bag frozen tater tots
Spread the meat mixture evenly on top of the tater tots.
Sprinkle the cheddar cheese over the meat mixture. Cover and bake for 20 minutes. Uncover and bake an additional 10-15 minutes or until cheese is melted.
8 oz. sharp cheddar cheese, shredded
Top with lettuce, black olives, chips, sour cream, salsa, and diced Roma tomato if desired. Serve immediately.
shredded lettuce, black olives, chips, sour cream, salsa, roma tomato