|Canned pork luncheon meat||12 Ounce, cut into 8 slices (1 Can)|
|Onion||1 Medium, sliced and separated into rings|
|Mushroom stems and pieces||4 Ounce, drained (1 Can)|
|Hamburger buns||4 , split and toasted|
Heat margarine in 10-inch skillet over medium heat until melted.
Cook luncheon meat in margarine until brown; turn.
Cook other sides until brown.
Remove from skillet; keep warm.
Cook onion and mushrooms in same skillet, stirring occasionally, until onion is tender.
Spread each bun half with mustard.
Place 2 slices meat, the onion mixture and lettuce on bottom half of each bun.
Top with remaining bun half.