Cut off the top of the onion and peel away the outer skin, leaving the root end intact. Starting about 1/2 inch from the root, make 12 to 16 evenly spaced cuts around the onion. Gently fan out the onion petals.
In one bowl, whisk together the eggs and milk until smooth. In another bowl, combine the flour with paprika, salt, cayenne pepper, ground black pepper, garlic powder, dried thyme, dried oregano, and ground cumin.
Dip the onion into the dry flour mixture first, shaking off any excess. Then, submerge it in the egg mixture so the liquid soaks into the petals. Finally, coat the onion again in the flour mixture, making sure the seasoning gets in between the petals.
Heat the vegetable oil in a deep pot or deep fryer to 350°F. Carefully lower the coated onion into the hot oil with the root side down. Fry for about 5-6 minutes until the bottom is golden.
Flip and fry for another 2 to 4 minutes until the entire onion is deep golden and crispy. Remove the onion and let it drain on paper towels. Serve warm, optionally with your favorite dipping sauce.