Preheat the air fryer to 360 degrees
Chop the Brussels sprouts in half and remove the stem
Toss the Brussels sprouts in enough oil to have a thin layer, mix in salt, pepper and garlic salt
Cook for 10 to 15 minutes. I normally do 15 minutes because I like mine very crispy. Take out the basket and toss the brussels sprouts around at the 5-minute mark. This will allow them to be cooked more evenly.