While the air fryer is preheating, slice the peppers and onions. Add the bell peppers and onions to a large bowl along with the olive oil, Italian seasoning, and balsamic vinegar.
Lay the seasoned bell peppers and onions in the air fryer, they'll be overlapping and won't be in a single layer.
Cook the vegetables for a total of 8-10 minutes, flipping or shaking the basket half way through cooking. The peppers were cooked through and soft after 8 minutes of cooking but to get them partially browned, continue cooking for a total of 10-12 minutes depending on your preference.
Transfer the air fryer bell peppers and onions to a serving bowl and mix in the balsamic vinegar if you're using it.
Serve and enjoy!
Notes
Any color of bell peppers works in the recipe whether it be green peppers, red, yellow, or orange.Instead of onions, why not mix the bell peppers with sliced mushrooms or how about all three?While the air fryer bell peppers are seasoned with balsamic vinegar and Italian seasoning in the recipe, to make simple roasted air fryer peppers, just use olive oil, salt, and pepper.Serve with Italian sausage, pork chops, or chicken.