Place the cornmeal, flour, baking powder and salt into a large mixing bowl and stir.Crack the egg into a medium mixing bowl and beat it with a fork until it is well mixed.
Add the chopped onion pieces and milk to the egg and mix well.Stir the egg, milk, and onion pieces into the cornmeal and flour mixture.
Place about 2-3 inches of oil in a deep-fat fryer or skillet over medium-high heat.When the oil is hot, carefully drop the batter into the pan. Use one heaping teaspoon of batter for each hush puppy. You may fry 5-6 hush puppies at once.The hush puppies will sink into the hot oil. Then they will rise to the top. After 1-2 minutes, the hush puppies will be golden brown.Use a slotted spoon to remove the hush puppies.