My son loves this potato salad....I also do a shrimp coleslaw he loves. Best made early in the day or the day before because it requires at least 8 hours of chilling time. Chilling time is not included in the prep time.
Bring water to a boil; add shrimp, and cook 3 to 5 minutes. Drain well; rinse with cold water. Chill. Once cool, peel and devein shrimp. Place the shrimp in a bowl; add the lemon juice and toss gently. Cover and chill.
Cook the potatoes in boiling water to cover 20 to 30 minutes or until tender; drain. Peel and cube the potatoes. Set aside.
Rub the cut side of the garlic on the inside of a large salad bowl; discard garlic. Combine the chilled shrimp, potato, celery, and green onions in the prepared salad bowl; toss gently to combine.
Combine the sour cream and remaining ingredients in a small bowl; stir well. Add the sour cream mixture to the potato mixture, tossing gently to coat evenly. Cover and chill at least 8 hours.