Preheat air fryer to 350 degrees.
In a medium bowl, add brussels sprouts, avocado oil, salt, pepper, garlic and balsamic vinegar. Toss gently until brussels are evenly coated.
Add brussel sprouts in a single layer to an air fryer basket lined with parchment paper, in a silicone basket, or lightly sprayed with oil.
Air fry for 6-7 minutes.
Add feta cheese and air fry for 5-6 additional minutes. Brussel leaves should be getting crispy and feta should be golden brown and melted.
Preheat oven to 425 degrees.
In a medium bowl, add brussels sprouts, avocado oil, salt, pepper, garlic and balsamic vinegar. Toss gently until brussels are evenly coated.
Add brussel sprouts in a single layer to prepared baking sheet lined with parchment paper or lightly sprayed with oil.
Roast brussel sprouts for ~12 minutes, stirring halfway through.
Add feta cheese and continue roasting for 7-8 more minutes until feta cheese is melty and golden brown.
