In a medium bowl, stir together the first six ingredients: Cornmeal, All-purpose flour, Sugar, Baking powder, Baking soda, and Salt. Make a well in the center of the mixture.
In a small bowl, combine the next three ingredients: Egg, Buttermilk, and Onion. Beat together until fully incorporated.
Add the egg mixture all at once to the flour mixture. Stir just until moistened; the batter should be lumpy.
In a 3-quart saucepan or deep fryer, heat about 2 inches (5 cm) of Vegetable oil to 375°F (190°C).
Using a slightly rounded tablespoon, drop the batter into the hot oil, making sure not to overcrowd the pan.
Fry the Hush Puppies for about 3 minutes or until golden brown, turning them once for even cooking.
Carefully remove them from the oil using a slotted spoon. Drain on paper towels to absorb any excess oil.
Serve warm. Enjoy them fresh out of the fryer!
