Preheat the air fryer to 375 degrees F.

Chop the brussel sprouts in half and transfer them to a large mixing bowl. Pour in the avocado oil and sprinkle with sea salt. Toss everything well until the brussels are coated with oil and salt.

Transfer the brussel sprouts to the air fryer and shake them into an even layer. Air fry for 15 minutes at 375, shaking half-way through.

While the brussel sprouts are cooking, melt the butter in the microwave and add the chopped garlic to it.

Transfer the brussel sprouts to a serving bowl and pour in the garlic butter mixture and stir well. If desired, add 1 to 2 teaspoons of balsamic vinegar. Taste the brussel sprouts for flavor and add sea salt to taste.

If desired, sprinkle the brussels with freshly grated parmesan cheese.

Serve alongside your main entrée and enjoy!