Cut chicken wings at joints. Discard the wing tips.
In a bowl, combine sake or sherry, soy sauce, and ginger root to make a marinade. Place chicken in a plastic bag, and set the bag in a bowl. Pour marinade over the chicken in the bag. Close the bag. Marinate in the refrigerator several hours or overnight, turning occasionally.
Drain chicken; pat dry with paper toweling. Coat chicken wings with cornstarch. Fry, 3 or 4 pieces at a time, in deep hot fat (365 degrees) for about 5 minutes. Drain on paper toweling.
Remove chicken to serving plate. Garnish with lemon slices.