Sauce:
Over low heat, melt butter in a non-stick skillet. Stir in whipping cream and blend well. Add parmesan cheese and stir until sauce thickens. Do not boil. Thicken sauce with more cheese, or thin with more cream. The sauce should generally be creamy.
Combine milk, water, & Alfredo sauce in a 2 quart saucepan. Add margarine, black pepper, & Greek seasoning. Bring to a boil over medium heat. Reduce heat & simmer 3 minutes, stirring constantly. Stir in cooked shrimp & simmer until heated.