1 cup butter or margarine, softened
1 small onion, minced
1 tablespoon poppy seeds
2 teaspoons Dijon mustard
1 teaspoon Worcestershire sauce
5 (7 1/2-ounce) packages party rolls
2 pounds thinly sliced ham, chopped
12 ounces Swiss cheese slices
Recipe
Beat butter and next 4 ingredients at medium speed with an electric mixer until blended.
Split rolls horizontally without separating; spread butter mixture evenly over bottom halves. Top with ham, cheese, and remaining halves of rolls.