Trim ends from snow peas.
Place snow peas in a steaming basket.
Plunge basket into boiling water, and remove immediately.
Place snow peas in a bowl of ice water to cool quickly.
Remove from water, and refrigerate.
Combine mayonnaise, sour cream, bouillon granules, garlic powder, and Worcestershire sauce, mix well.
Stir in water chestnuts, pimiento, and green onions.
Chill 1 to 2 hours.
Serve with snow peas.