Add avocado oil to a large skillet over medium-high heat. Cook onion in the hot oil, stirring occasionally, until the onion is golden brown and caramelized. This can take up to 20 minutes. *If the onion starts to burn, reduce the heat and add a little more oil to the pan.
Remove the caramelized onions to a plate and add the ground beef in the same skillet, breaking up with a spoon until cooked through and crumbled. Drain any excess fat from the pan. Return the pan to the stove top and add in the garlic, onion onion seasoning and seasoned pepper. Cook for about 30 seconds, until fragrant.
Add in the rice, beef stock, onion soup mix, frozen peas and carrots and the caramelized onions. Stir to combine and bring mixture to a boil. Reduce the heat to low, cover and let cook for 18 to 20 minutes, until the rice is tender.
Fluff the rice and ground beef mixture with a spoon, then add in the shredded cheese. Stir until combined and then serve.
Notes
UPDATE (9/14/2026): The original recipe called for 3/4 cup Tastefully Simple French Onion Skillet Sauce, but this is no longer available for purchase. I'm updating the recipe to substitute the sauce with 1oz of onion soup mix. The current recipe amounts and instructions above should be correct.