The Best 2-Ingredient Air Fryer Onion Chips (Easy Keto Snack!)

Using a mandolin (strongly recommended) or a very sharp knife, slice the onions paper-thin, about 1/4 inch (6mm) or less. Thinner is crispier.

Preheat the air fryer to 375° F (190°C). Line the air fryer basket with a piece of parchment paper. Safety Note: The paper must be weighed down by food and not be loose.

Working in batches, sprinkle a thin, even layer of Parmesan cheese (about 1/4 of the total cheese) onto the parchment paper. Arrange the onion rings in a single, slightly overlapping layer on top of the cheese. Lightly brush or spray the onions with olive oil and sprinkle with seasonings (if using).

Air fry at 375° F (190°C) for $8-10 text{ minutes}$. Check at 7 minutes, they are done when the cheese is deep golden-brown and crispy at the edges.

Carefully remove the parchment paper from the basket. This is the most important step: Let the chips cool on the counter for 5-10 minutes. They will become perfectly crispy as they cool. Once cool, break into chips and serve.