Cube the steak, then freeze for easier slicing on mandolin, slice 1/8th inch thin, (3 mm), across the grain. Slice other ingredients also 1/8th inch thick: 6 slices gouda cheese, 4 slices yellow onion, 8 slices green pepper, 4 shitake mushrooms. Sprinkle few drops of balsamic vinegar and juice of small lime over the beef.

Heat large cast iron skillet, when hot, spray olive oil on top, carmelize onions and green peppers till glazed. Then add mushrooms, stir fry till browned. Remove from pan, add beef to pan juices, stir till carmelized, add other ingredients, add cheese on top, melt and stir through the mix.

Fill warm sour dough roll with hot beef and cheese mix, toothpicks on top to keep closed, cut in half. Serve with pickled carrots, cucumber, boiler onions or sweet peppers on the side. Enjoy.