Preheat air fryer to 400°F. *If your air fryer doesn't have a preheat setting, just turn it on about 10 minutes before you start cooking.
In a medium pot over high heat, bring 1.5 cups water or broth to a boil. Reduce heat to low, add uncooked rice, cover, and simmer for 18 minutes. Let stand 5 minutes, then fluff with a fork.
¾ cups white rice
Meanwhile, cut off the tops of the bell peppers and remove the seeds and ribs. Place peppers in the air fryer basket and cook at 400°F for 7 minutes to par-cook. After removing the peppers, reduce the air fryer to 350°F.
4 bell peppers
While the unfilled peppers are cooking, heat a large skillet over medium-high heat. Add ground beef and cook, breaking up the meat with a spoon as it cooks, until no longer pink, about 6 minutes.
2 pounds lean ground beef
Add taco seasoning, tomato paste, and water to the beef, stirring until meat is evenly coated. Stir in cooked rice, diced tomatoes with green chiles, black beans, and 1/2 cup shredded cheese. Season with salt and pepper to taste.
¾ cups white rice, 1 cup diced tomatoes with green chiles, 1 cup canned black beans, 2 tablespoons taco seasoning, 1 tablespoon tomato paste, 2 tablespoons water, 1 ½ cups shredded cheddar cheese
Remove par-cooked peppers from air fryer. Fill each pepper to the top with beef mixture, packing gently.
Place stuffed peppers in air fryer basket. Cook at 350°F for 15 minutes.
Top peppers with remaining 1 cup of cheese and cook for 2-3 more minutes, until cheese melts. Remove stuffed peppers from air fryer and let them cool for 5 minutes before serving.
1 ½ cups shredded cheddar cheese
Notes
Use leftover cooked rice to save some time!
You can skip par-cooking the empty peppers and increase the cook time by 6-10 minutes instead.
There may be filling left over—save it for another meal or use it to make extra servings.