Begin by preparing the onion. Cut a very small piece off the root and stem ends, and remove the skin from the onion.
Put the onion on a cutting board, with the stem side facing up. Cut the onion into quarters, but make sure to stop about ¾ of an inch from the bottom so that the onion remains whole.
Cut each quarter into thirds, again stopping about ¾ of an inch from the bottom.
In a small bowl, mix together flour, garlic powder, salt, and paprika. In a separate bowl, whisk together water and egg.
Put the onion in a shallow bowl, and sprinkle it with the flour mixture. Gently separate the onion wedges to coat all surfaces. Shake off any excess flour and put it in a separate bowl.
Stir cornmeal into the flour mixture that you set aside earlier. Put the onion back in the shallow bowl and brush all surfaces evenly with the egg mixture. Sprinkle with the flour-cornmeal mixture, making sure all surfaces are coated.
If your air fryer needs preheating, do so now to 375°F. Spray the air fryer basket with nonstick spray.
Carefully place the onion in the basket and spray it generously with nonstick spray. Air-fry until the breading is crispy and the onion is tender, which should take around 15-18 minutes.
While the onion is cooking, make the sauce by mixing together yogurt, mayonnaise, horseradish, ketchup, and the remaining ½ tsp of garlic powder.
Serve it with the sauce.
Notes
Serving size: one-sixth of onion and about 1 tbsp sauce2 WW Points
Tips and Tricks
Cutting the onion: Slice slowly and stop before the knife reaches the bottom so the base stays together and the onion can bloom without falling apart.Opening the petals: After cutting, gently spread the sections apart with your fingers. Do this over the dish so loose pieces still catch the coating.Coating evenly: Shake off extra flour before adding the egg mixture, then press the cornmeal coating lightly onto the petals so it sticks well.Keeping the basket clean: Spray the air fryer basket before adding the onion to help prevent sticking and make cleanup easier.Checking for doneness: If the outside browns too fast, lower the temperature slightly and cook a few more minutes until the center of the onion is tender.Reheating in air fryer:Reheat in Air Fryer - Place leftover pieces in the air fryer basket. Heat at 350°F for a few minutes until warm and crisp again.