Prepare the Onion
Peel the onion and cut about ½ inch off the top. Leave the root intact so the onion stays together. Place the onion cut-side down and carefully make 12–16 vertical cuts from top to root to create petal-like sections.Open the Onion Bloom
Turn the onion over and gently spread the sections apart using your fingers. This will help create the classic blooming flower shape.Prepare the Seasoned Flour
In a large bowl, mix together flour, paprika, garlic powder, salt, black pepper, and cayenne pepper. This seasoned coating gives the onion its bold flavor.Prepare the Wet Batter
In another bowl, whisk together egg and buttermilk until smooth. The buttermilk helps tenderize the onion and creates a crispy crust.Coat the Onion
First, coat the onion thoroughly with the seasoned flour mixture, making sure it gets between the petals.Next, dip the onion into the egg and buttermilk mixture.Finally, coat it again with the seasoned flour for an extra crispy texture.Heat the Oil
Heat vegetable oil in a deep fryer or heavy pot to 375°F (190°C). The oil should be deep enough to fully submerge the onion.Fry the Onion
Carefully place the onion into the hot oil cut-side down. Fry for about 4–6 minutes or until the onion becomes golden brown and crispy.Drain Excess Oil
Remove the onion using tongs or a slotted spoon and place it on paper towels to drain excess oil.Prepare the Dipping Sauce
In a small bowl, mix mayonnaise, ketchup, horseradish, paprika, garlic powder, cayenne pepper, and salt until smooth.Serve
Place the blooming onion on a serving plate and serve warm with the dipping sauce in the center.
