Welcome to Key Ingredient.
SEE MORE RECIPES!
| ⅓ | cup butter, melted |
| 2 | tablespoons prepared mustard |
| 1 | small chopped onion |
| 1 | tablespoon poppy seeds |
| 6 | hamburger buns |
| 6 | slices ham |
| 6 | slices Swiss or American cheese |
Combine butter, mustard, onion, and poppy seeds. Spread on inside of hamburger buns. Place 1 slice ham and 1 slice cheese on each bun. Spread sauce on top of buns. Heat in oven on cookie sheet 15 minutes at 350 degrees.

See more comments