Preheat your air fryer to 390°F (195° Celsius).
Wash peppers and pat them dry.
Cut onions and peppers. Slice them how you prefer. I cut my peppers into approximately 1-inch wide julienne strips. And slice onions into half-circles.
In a large bowl add sliced peppers, onions, oil, salt & pepper to taste and seasoning.
Toss all ingredients until fully coated.
Transfer veggies to the air fryer basket/tray, and lay them in a single layer.
Air fry them for 10 to 15 minutes (toss them every five minutes so that they cook evenly from each side). I did mine for 15 minutes total because I love my peppers and onions charred with beautiful wrinkly skin.
Fry them until their desired color and crispiness.
When done the onions should be translucent and the peppers should be golden brown and slightly crispy.