1/3cupblanched almond flour + 2 tablespoons reserved for sprinkling
Cut top off onions, leaving the bottom end with the roots intact. Place onion root side up onto a cutting board. Make vertical cuts down through to the bottom, all around the onion to form small strips. Be sure to leave the onion attached at the root. You want the onion to "fan" out to form that blooming onion shape, but still all be attached.
Add the onion to cold water and allow to soak for 1 hour. This will help to plump up the pieces and also to help it fan out better. Remove from water and pat dry.
To a bowl, add remaining ingredients, except for the 2 extra tablespoons of almond flour. Stir in water to form a thick batter. Coat the entire onion in the batter. Sprinkle with the remaining 2 tablespoons of almond flour.
Coat bottom of the air fryer in cooking spray, and place onion inside, root side down. Spray with cooking spray.
Cook for 25 minutes at 375F.
Nutrition Facts (per serving, 4 servings per onion): 97 calories, 6 g total fat, 8 g total carbs, 2 g fiber (6 g net carbs), 3 g protein