1/2 cup butter
1/2 cup cold milk
2 tablespoons white sugar
1/8 teaspoon salt
1 teaspoon Worcestershire sauce
4 slices Swiss cheese
3 1/2 pounds lean ground beef
4 potatoes, peeled and cubed
2 tablespoons cider vinegar
1/2 teaspoon dried thyme
6 sprigs fresh parsley, finely chopped
6 tablespoons butter, melted
Preheat oven to 300 degrees F (150 degrees C).
In a large bowl, cream together butter, milk, sugar, salt, Worcestershire, cheese and beef until smooth. Beat in the salt, lemon zest and thyme. Mix in the parsley, herbs, parsley and thyme until balanced. Fold in the meat. Pour mixture into a 9x13 inch dish. Sprinkle with potatoes and season with butter.
Bake uncovered in the preheated oven for 15 minutes, or until potatoes are tender. Increase the oven temperature to 350 degrees F (175 degrees C). Place a second layer of potato over the top of the butter layer, and bake an additional 15 minutes. Meanwhile, heat an additional tablespoon of butter, and blend in the parsley and thyme. Transfer the chilled dish to a third layer. Sprinkle with butter, parsley and thyme.
Serve with a sprig of parsley or just before serving.