In a microwave-safe bowl, melt butter, then mix in dried mustard, Worchestershire sauce, dired minced onion and poppy seeds.
Cute entire pack of dinner rolls in half, horizontally (keeping the top and bottom halves separate but intact. All 12 dinner roll tops should be connected, as should all 12 bottoms).
Place bottom half of rolls in a baking pan and cover them with ham, then cheese. Then, cover the ham and cheese with the top halves of the rolls.
Drizzle butter mixtrure over the top of rolls, making sure onion and poppy seeds are well distributed. Refigerate your rolls several hours or overnight.
Once rolls are ready to be baked, preheat oven to 350 degrees F and bake for 15-20 minutes. Once finished, cut apart the rolls for serving.