In the large bowl mix sliced pepper and onion, Provencal herbs, salt and ground pepper to taste. Also, add olive oil to this mixture.
Cut the pork tenderloin into 4-6 large pieces, scrub with salt, ground pepper, and mustard.
Preheat your Air Fryer to 370-390° F.
Place vegetable mixture to the air fryer.
Coat meat pieces with olive oil and place them up to the vegetables.
Cook for 15 minutes until meat and vegetables will become roasted.
Turn the meat and vegetable in the middle of cooking process.