Wash the kale thoroughly under cold water, and remove the stems from the leaves. Tear or chop the kale leaves into bite-sized pieces.
Use a salad spinner to dry the kale, or pat it dry with paper towels. It's important to remove as much moisture as possible for the crispiest chips.
In a large mixing bowl, combine the kale pieces with olive oil, sea salt, and any optional seasonings like garlic powder and nutritional yeast. Toss until the kale is evenly coated.
Preheat your air fryer to 350°F (175°C) for about 3 minutes.
Place the kale in a single layer in the air fryer basket. Avoid overcrowding; cook in batches if necessary.
Air fry the kale for 6-8 minutes, shaking the basket halfway through to ensure even cooking. Keep an eye on them to prevent burning.
Once the kale chips are crisp and slightly browned, remove them from the air fryer and let them cool for a minute.
Enjoy your air fryer kale chips immediately, or store them in an airtight container for later!