Peel the onion and cut an inch off of the top. Place the onion flat side down on a cutting board root-end up. Cut from the root down in 12-16 sections around the onion to form the petals. (See video linked below)
Place the onion in the flour mixture and cover well.
Then place the onion in the egg/milk mixture, and then dunk it back in the flour once more.
Fry at 375 degrees Fahrenheit for 4-5 minutes. Flip and fry for another 4-5 minutes or until golden brown.