Start by prepping the ingredients. You can slice the mushrooms or buy them pre-sliced. Cut the onion into slices as well.
Add the mushroom and onion slices to a mixing bowl. Drizzle with oil and sprinkle in seasonings. Use a kitchen utensil to mix everything up and coat the mushrooms and onions evenly in the toppings.
Open up the air fryer and add mushrooms and onions to the basket. Heat at 400 degrees for 14 minutes, pausing halfway through cooking time to pull the basket out and mix up the contents.
Once the cooking time is up, use a spatula to move mushrooms and onions to a serving dish or bowl.
Video
Notes
Use any kind of vegetable oil you prefer... or omit it entirely. It does add flavor to the final dish
Cook 1 large onion or 2 small onions
Choose any seasonings you love on mushrooms and onions. We kept it simple with salt, pepper, and garlic powder
Be sure to stir up the mushrooms and onions halfway through cooking time, to ensure even browning of ingredients