01 - Peel the onions and trim the root ends just enough so they stand upright. Cut each onion vertically into quarters, slicing downwards without severing the base. Rotate and make four additional cuts between the first, preserving the core. Use your fingers to gently separate the petals.
02 - Submerge onions in ice water for 10 minutes to promote blooming. Drain thoroughly and dry with paper towels.
03 - In a mixing bowl, whisk together the all-purpose flour, cornstarch, paprika, garlic powder, onion powder, cayenne pepper, salt, and black pepper until evenly blended.
04 - In a separate bowl, beat the eggs with the whole milk until smooth.
05 - Dredge each onion in the seasoned flour mixture, shake off excess, dip in egg mixture, then dredge again in flour mixture. Gently press the petals so coating adheres thoroughly.
06 - Pour vegetable oil into a deep fryer or heavy-bottomed pot to a depth sufficient for submerging the onions. Heat the oil to 350°F (175°C).
07 - Working in batches, lower onions into the hot oil cut side down. Fry 2–3 minutes, then turn and continue frying 2–3 more minutes until uniformly golden and crispy. Remove with a slotted spoon and drain on paper towels.
08 - Blend mayonnaise, ketchup, horseradish, smoked paprika, garlic powder, salt, and black pepper in a bowl until smooth.
09 - Present crispy mini bloomin’ onions warm, accompanied by the dipping sauce.