Cut the red bell peppers in half, top to bottom. Carefully trim out the seeds and ribs from the inside.
Place the four pepper halves, cut side down, in the basket of your air fryer. Cook at 375 degrees F for 10 minutes.
While the peppers are cooking, heat a non-stick skillet over medium-high heat. Add the ground sirloin and cook until no longer pink, breaking it up with a heat-safe spatula as it cooks.
Stir in the salsa and taco seasoning and allow to simmer for a few minutes.
Stir in the corn, black beans and cream cheese. Remove from heat and stir until the cream cheese is completely combined.
Remove the peppers and fill each of them generously. Return them to the air fryer basket, filling side up. You'll have extra filling. Make another round of peppers. Or save the filling and mix it into Kraft macaroni and cheese with some extra salsa for another meal.
Cook at 400 degrees F for 5 minutes. Open the air fryer, top each pepper with some shredded cheese and heat again at 400 degrees for 1-2 minutes, just until the cheese is melted.
Serve the peppers topped with sour cream and taco sauce.