- 1
Prepare the Dipping Sauce: In a small bowl, whisk together all dipping sauce ingredients until well combined. Cover and refrigerate while you prepare the onion.
- 2
Prepare the Onion: Cut about 1/2 inch off the top (stem end) of the onion, leaving the root end intact. Peel off the outer layers. Place the onion cut-side down on a cutting board. Using a sharp knife, make 12-16 even cuts from the top down towards the root, stopping about 1/2 to 3/4 inch from the root to keep the onion intact. Gently separate the 'petals' of the onion. You can submerge it in ice water for 15-20 minutes to help the petals open further.
- 3
Prepare the Wet Batter: In a large bowl, whisk together the 1 1/2 cups flour, 1/2 cup cornstarch, baking powder, 1 teaspoon salt, 1 teaspoon black pepper, garlic powder, onion powder, paprika, and cayenne pepper. In a separate bowl, whisk together the beaten egg, milk, and hot sauce. Gradually pour the wet ingredients into the dry ingredients, whisking until just combined (a few lumps are okay).
- 4
Prepare the Dry Dredge: In another large bowl, whisk together the 1 cup flour, 1/4 cup cornstarch, 1/2 teaspoon salt, 1/2 teaspoon black pepper, and 1/2 teaspoon paprika.
- 5
Heat the Oil: In a large, heavy-bottomed pot or Dutch oven, pour the vegetable oil to a depth of about 3-4 inches. Heat the oil over medium-high heat until it reaches 350-375°F (175-190°C). Use a candy/deep-fry thermometer to monitor the temperature.
- 6
Batter the Onion: Thoroughly pat the opened onion dry with paper towels. First, dredge the entire onion in the dry dredge, ensuring all surfaces are coated, shaking off excess. Next, completely submerge the onion in the wet batter, using a spoon to help coat all the petals. Lift the onion, allowing excess batter to drip off. Immediately transfer the wet-battered onion back into the dry dredge, ensuring every crevice is coated. Press the dry dredge onto the petals to ensure full coverage.
- 7
Fry the Onion: Carefully lower the battered onion into the hot oil, cut-side down first. Fry for about 5-7 minutes, basting the top with hot oil, until golden brown. Carefully flip the onion with tongs and continue to fry for another 5-8 minutes, or until the entire blossom is deep golden brown and crispy. Adjust heat as necessary to maintain oil temperature.
- 8
Drain and Serve: Carefully remove the fried onion from the oil and place it on a wire rack set over a baking sheet lined with paper towels to drain excess oil. Lightly season with a pinch of salt if desired. Place the onion on a serving platter and serve immediately with the prepared dipping sauce in the center.
