Preheat your air fryer to 375°F (190°C) and lightly grease the basket with avocado oil.
Peel the sweet onion and slice into thick rings, separating the layers carefully.
In a shallow bowl, whisk together the arrowroot powder, almond flour, garlic powder, smoked paprika, sea salt, and black pepper.
Slowly whisk the light beer into the dry ingredients until a thick, smooth batter forms.
Season the chicken breast with a pinch of salt and pepper, then grill in a hot pan for 5-6 minutes per side until fully cooked.
While the chicken rests, dip each onion ring into the beer batter, ensuring it is fully coated, and place in a single layer in the air fryer basket.
Air fry the onion rings for 10-12 minutes, flipping halfway through, until they are golden brown and crispy.
Serve the hot onion rings immediately alongside the sliced grilled chicken breast.