1/4 lb. butter, at room temperature
1 tsp. onion, finely chopped
1 tbsp. poppy seed
1 tbsp. prepared mustard
12 hamburger buns
12 slices ham
12 slices cheese, Swiss or other

Mix butter, onion, poppy seed and mustard. Spread on insides, tops and bottoms of buns. Place ham and cheese on each bun. Wrap in tin foil. Place in shallow pan and heat in 300 degree oven for 20-30 minutes. Sandwiches should be served warm. Sandwiches can be frozen and heated for later use.