CHICKEN:
1 (3-ounce) piece ginger, unpeeled, cut into 1/2 inch pieces
4 garlic cloves, peeled
1 cup water
1/2 cup soy sauce
3 tablespoons packed light brown sugar
1 tablespoon toasted sesame oil
2 pounds boneless, skinless chicken thigh, trimmed and halved crosswise
2 1/4 cups potato starch
2 tablespoons sesame seeds
1 1/2 teaspoons baking powder
salt and pepper
3 quarts peanut or vegetable oil

DIPING SAUCE
1/2 cup seasoned rice vinegar
1/4 cup soy sauce
1/4 cup lemon juice (2 lemons)
Pepper