- In a bowl, mix together the onion, salt, baking soda, flour and cornmeal. 
- Heat oil in a saucepan over medium-high heat until it reaches 375 degrees F (190 degrees C). 
- In another bowl, mix together the buttermilk and egg. 
- Add the wet ingredients to the dry ingredients and mix together. 
- Drop tablespoons of the batter into the hot oil and fry until golden brown, about 2 minutes per side. 
- Remove the hush puppies from the oil and drain on paper towels. Serve immediately.