I am looking for a recipe that I used to prepare years ago, but lost. It used "finger rolls" (in aluminum heatable tray). The sheet of rolls was sliced horizontally. A mixture of melted butter(?), dehydrated onions, and mustard was spread on each half of the sheet of rolls. A layer of ham and a layer of swiss was added. Then the layers were put together and the rolls were baked in their tray in the oven for a short time. I vaguely remember sprinkling poppy seeds on top of them. When finished, the rolls were sliced individually.

Does anyone recognize this? If so, please post the exact instructions. Thank You!