Please read about Deep-Frying.
Combine in a medium bowl:
Whisk in until smooth, adding the amount needed to reach the consistency of pancake batter:
To fry, follow the directions in the specific recipe. Or, for a general procedure, heat to 365°F in a deep-fryer, deep heavy pot, or Dutch oven:
Pat the food dry. Drop 3 to 4 pieces of food into the batter at a time and turn to coat. Using tongs, lift out the food and drop gently into the hot fat. Do not crowd the pot. Fry until golden brown, 3 to 5 minutes, turning once or twice. Drain on a rack or on paper towels.