Preheat oil in a deep fryer or in a large pot until it reaches 350 degrees F.
Slice chicken into thin strips. Dust chicken in corn starch.
In a large bowl, add egg, salt, and club soda and mix together with chop sticks. Add in cake flour in 1/2 cup batches and use chopsticks to lightly stir it together. It’s okay if there are clumps. Finished batter should be a thin pancake batter consistency. Don’t over-mix it.
Dunk dusted chicken in tempura batter and then drag each piece through the oil so it cooks slightly before letting it go. Don’t just drop them in the oil or they will sink to the bottom and stick. Cook the chicken in batches for 4-5 minutes until they are golden brown and cooked through. Test a thicker piece to make sure they are done.
Drain chicken tempura on some paper towels and serve as an appetizer or over rice as a meal with soy sauce and chili garlic sauce.