In a medium bowl, combine flour, spices, salt and pepper. Reserve.
In another medium bowl, whisk together eggs and milk until combined. Set aside.
Cut off ½-inch from the pointy end of the onion while leaving the other end of root intact. Then remove the papery skin.
Place the onion cut-side down on a cutting board. Starting ¾-inch from the root, cut vertically downward all the way to the board using a sharp knife.
Repeat vertical cuts downward about 1/2-inch apart on the edge, taking care not to overlap with previous cuts. You should get 10-15 cuts in total.
Turn the onion over and gently open up the "petals" of the onion with your fingers until it resembles a flower. Set aside.
Dip the onion into reserved flour mixture to cover completely. Then gently shake off excess flour.
Gently dip into reserved egg mixture to cover completely. For best results, let the onion soak in the batter for 10 minutes.
Return onion to the flour mixture one more time and cover completely.
Place the onion on a plate and freeze for 30-60 min to set.
Fill a deep fryer or medium saucepan with 3 inches of oil and heat to 350°F. Line a plate with paper towel and set aside.
Fry onion for 3-4 minutes until golden brown. Then turn it over using a slotted spoon and cook several minutes more until golden brown.
Remove onion to a prepared plate. Serve with optional dipping sauce and enjoy!