Fill the deep fryer with oil
cut onions 1/4 inch slices and separate slices
Whisk together flour, cornstarch, and baking powder
In a separate bowl, combine eggs and buttermilk.
Dip onions in buttermilk mixture and then in the flour mixture.
Fry 2 to 3 minutes until golden.
Drain on paper towel.
Sprinkle with Cajun seasoning.