In medium saucepan over low heat, melt butter and saute onion with Worchester sauce, salt and pepper until onions are caramelized. Add water and potatoes. Cook over medium heat until potatoes are tender. (12-15 minutes).
Reduce heat and add oysters and liquor (natural juice in container).
Continue cooking 3-5 minutes.
Let stand for 10 minutes on low heat, add cream. Season to taste.