No-Fuss method for perfectly cooked mushrooms and onions using an air fryer. Serve them as a side dish or as a burger topping, in an omelete, and so many other ways!
Slice the onion into ½" strips. Quarter the cremini mushrooms. Make sure the mushrooms are not wet when adding them to the air fryer or too much steam will be produced and the texture will be different.
1 medium sweet onion, 8 ounces mushrooms
Add the prepared onions and mushrooms to the inner cooking surface of your air fryer. So, if you are using the Ninja Foodi Pressure Cooker & Air Crisper, this would be the inner pot. On basket style air fryers, this would be the basket without a rack.
Add the olive oil, salt, and black pepper. Use tongs to toss the vegetables around so they are evenly coated.
2 Tablespoons olive oil, ¼ teaspoon fine grind sea salt, ⅛-¼ teaspoon black pepper
If you want to add the optional seasonings, do that now and toss to coat.
Close the air fryer and select the air fry function, set the temperature to 400℉/200℃ and the time for 30 minutes. It does not take 30 minutes to finish cooking, but I like to have the extra time on the clock. Hit start.
After 8-10 minutes, open the air fryer and toss the onions and mushrooms around. You will see more liquid has collected in the bottom and you want to coat the vegetables with it. Continue air frying another 7-10 minutes.
After 17 minutes, open the air fryer and taste one of the onion slices and a mushroom piece. If they are the correct texture for you and seasoned well, then proceed to the final touches. If you want them softer, continue air frying for another 5-10 minutes or until they are the texture you like. Add salt and pepper if needed, but if you are going to add salted butter at the end, then be careful with the salt.
Once the mushrooms and onions are the texture you like, add the butter and close the lid or drawere of the air fryer. With the air fryer turned off, leave the mushrooms and onions inside so the butter melts from the residual heat for 3-5 minutes.
2 Tablespoons butter
Toss the mushrooms and onions around with tongs and transfer to a serving bowl. Top with dry or fresh parsley if desired. if you didn't use dry thyme leaves, you can garnish with fresh thyme leaves instead of parsley. Serve & Enjoy!
If you want to make a double or triple batch, just increase the ingredients accordingly. Depending on your air fryer, you may need to cook in batches. When making a double or triple batch all at once, plan on increasing the cooking time and toss the mushrooms and onions around every 7-10 minutes so they evenly cook.