Preheat the oven to 375°. Prepare a 9x13 baking dish with cooking spray. Set aside.
Cook the ground beef in a large skillet until no longer pink. Add the onions, garlic, and peppers for 2-3 minutes or until tender.
Add the beans, corn, and tomatoes.
Stir in the taco seasoning, sour cream, and half the cheese. Cook until warm and bubbly. Taste and season with salt and black pepper if desired.
Spread the beef mixture in an even layer in the prepared baking dish.
Top with a single layer of tater tots. Sprinkle with remaining cheese.
Bake for 30 minutes or until the casserole is bubbly and the tater tots are lightly browned and crispy.
Remove from the oven and garnish with parsley or cilantro.