Ingredients:

  • 1 large yellow onion (about 1 pound / 450g)
  • 1 cup (120g) all-purpose flour, plus more for dusting
  • 1 tbsp cornstarch (10g)
  • 1 tsp paprika (5g)
  • 1 tsp garlic powder (5g)
  • 1 tsp onion powder (5g)
  • 1/2 tsp cayenne pepper (2.5g) (optional, for a bit of kick!)
  • 1 tsp dried oregano (5g)
  • 1/2 tsp salt (2.5g)
  • 1/4 tsp black pepper (1.25g)
  • 1 large egg, lightly beaten
  • 1 cup (240ml) milk
  • Vegetable oil, for frying (about 6-8 cups/1.4-1.9 litres)
  • 1 cup (240g) mayonnaise
  • 1/4 cup (60ml) ketchup
  • 2 tbsp prepared horseradish (30g)
  • 1 tsp Worcestershire sauce (5ml)
  • 1/2 tsp paprika (2.5g)
  • 1/4 tsp garlic powder (1.25g)
  • Pinch of cayenne pepper (optional)

Instructions:

  1. Peel the onion, leaving the root end intact. This holds the onion together.
  2. Carefully cut downwards from the top of the onion towards the root, stopping about 1/2 inch (1 cm) from the root. Make the first cuts about 1/2 inch (1 cm) apart. Repeat, making a second set of cuts in between the first set to create more petals. Invert the onion and gently separate the petals.
  3. Place the cut onion in a bowl of ice water for at least 30 minutes. This helps the petals open up further.
  4. In a large bowl, whisk together the flour, cornstarch, paprika, garlic powder, onion powder, cayenne pepper (if using), salt, pepper, and oregano.
  5. In a separate bowl, whisk together the egg and milk.
  6. Remove the onion from the ice water and pat it dry with paper towels. Dust the onion thoroughly with flour, ensuring all the petals are coated.
  7. Dip the floured onion into the egg mixture, making sure all the petals are coated.
  8. Return the onion to the flour mixture and dredge again, ensuring a thick, even coating.
  9. Heat the vegetable oil in a large pot or deep fryer to 350°F (175°C).
  10. Carefully lower the battered onion into the hot oil, root-side up. Fry for 3-4 minutes per side, or until golden brown and crispy.
  11. Remove the onion from the oil with a slotted spoon and place it on a wire rack lined with paper towels to drain excess oil. Serve immediately with the dipping sauce.
  12. In a medium bowl, whisk together the mayonnaise, ketchup, horseradish, Worcestershire sauce, paprika, garlic powder, and cayenne pepper (if using) until well combined.