I remember the first time I ate these sandwiches. It was after my Grandma passed away right before Christmas in 1989 while I was a senior in college. My mother-in-law (then boyfriend's mom) sent a couple dozen of these buns with us for the funeral. They were well received by my family—a yummy warm sandwich that our family didn't have to prepare! She took it a step further by making homemade buns (as she always did) instead of using store-bought buns.
2 lbs. sliced ham (shaved is best)
8 slices swiss cheese (If slices are really thin, use 1-1/2 to 2 slices per bun)
½ cup butter or margarine
¼ cup mustard
¼ cup chopped onion
1 tsp. poppy seeds (I usually don’t use)
Melt butter, add remaining ingredients—mustard, onion, and poppy seeds. Spread on both sides of hamburger buns, put ham and cheese slices on buns, individually wrap in foil. Bake at 350 degrees until the cheese melts—15-20 minutes.
Make a mess of them--they freeze well!