The Ultimate Patty Melt Burger - cooking recipe

Ingredients

2 lbs ground sirloin
3 -4 medium onions, sliced
1/2 lb bacon
1/2 lb mushroom, sliced
12 slices rye bread (a hearty, thick-sliced one with seeds is best)
12 slices swiss cheese
butter

Preparation

Cut the bacon strips in half. Fry to preferred doneness (I like mine moderately soft).
Fry onions in a little butter over medium to medium-high heat until cooked and browned.
Fry mushrooms in butter or bacon grease until nicely cooked and a little browned.
Form ground sirloin into 6, slightly oval patties. Fry or grill to preferred doneness (I like medium-well).
While patties are cooking, make 6 sandwiches of rye bread and cheese. Butter the outsides and cook like a normal grilled-cheese sandwich -- in restaurant-speak this is a \"set-up\".
When set-ups are ready them pry them open and set them on the individual plates.
Put cooked patties on one side of the set-up. Top with bacon strips, onions, and mushrooms.
Close sandwiches, pin with frilly toothpicks, and cut in half.
Offer mayonnaise and/or mustard (preferably brown or Dijon), at the table.
I prefer to offer coleslaw (try Recipe #209944 ), or a green salad but really crisp french fries and a pickle on the side are customary.