Step 1

For the SauceCombine mayonnaise, ketchup, horseradish, paprika, salt, black pepper, and cayenne pepper in a small bowl or ramekin; mix well. Set aside when done.

Step 5

For the OnionWhisk together egg and milk in a medium sized bowl. In a separate bowl mix flour, salt, cayenne pepper, black pepper, garlic powder, thyme, oregano, and cumin.

Step 9

Cut onion approximately 3/4 to 1 inch off of the top and bottom of the onion; remove skin. Remove the 1-inch diameter core from the middle of the onion. Using a large, sharp knife, slice down the center of the onion about 3/4 of the way down, turn 90 degrees and slice again. Keep slicing the sections in half, being careful not to cut to the bottom, until you have 16 sections. Spread the petals apart to make coating easier.

Step 13

Dip the onion in the milk, then coat well with the flour mixture. Separate the petals again and sprinkle the flour mixture between them. Once you have coated all of the petals well, dip it into the milk and into the flour mixture again.

Step 17

Pour 2 quarts of vegetable oil into a deep fryer or deep pot. Preheat the oil to 350 degrees Fahrenheit. Holding the onion right side up fry the onion for 10 minutes or until onion is golden brown. Remove from oil and set on paper towels to drain. Open the center of the onion wide so that you can put the bowl/ramekin of sauce in the center.