In a skillet, cook the ground beef and diced onion over medium heat until the beef is browned and the onion is soft.
Drain any excess fat from the skillet.
Add the chili beans, diced tomatoes, and taco seasoning to the skillet. Stir to combine.
Transfer the mixture to a baking dish and spread it out evenly.
Sprinkle half of the shredded cheddar cheese over the mixture.
Arrange the frozen tater tots in a single layer on top of the cheese.
Bake in the preheated oven for 30-35 minutes, or until the tater tots are golden brown and crispy.
Remove from the oven and sprinkle the remaining cheddar cheese on top. Return to the oven for an additional 5-10 minutes, or until the cheese is melted and bubbly.
Let the casserole cool for a few minutes before serving. Enjoy!
Notes:
This casserole is perfect for a cozy family dinner or a potluck gathering.