Heat a large oven-safe skillet over medium heat and spray with avocado oil spray (or olive oil).
Add the ground beef and onions and cook for 8-10 minutes until the meat is no longer pink and the onions are soft.
Preheat the oven to Broil and place the rack in the middle setting.
Add the taco seasoning and salsa to the ground beef and onions and stir well to combine.
Add the drained black beans, undrained corn, and undrained diced tomatoes to the skillet. Stir, and simmer for 5-6 minutes until most of the liquid has cooked down.
Add the cooked rice to the skillet, stir well, and top with the shredded cheese.
Broil, watching carefully, until cheese is bubbly (about a minute or so). Garnish and serve.
