Whisk the chicken eggs lightly, stirring in the milk as you go.
In a separate bowl, mix the flour, baking powder, and salt. Stir the egg mixture into the flour mixture, then beat in 1 teaspoon of cooking oil.
When the oil in the deep fryer reaches 375 degrees, dip each fish into the batter and deep-fry for a few minutes, until golden brown. If you have a large batch of fish, fry them just a few at a time (depending on the size of your fryer) so that the oil will stay very hot. Do not overcook