This is an old recipe that my mom used to make when we were growing up. This is so good and just tastes like good home cookin'.
Thin sliced sandwich steak (I had six pieces)
1 package baby bella mushrooms, coarsely chopped
1 medium sweet onion, diced
2 cloves garlic, minced
2 tablespoons butter
1 cup Italian style breadcrumbs
1 envelope onion soup mix, divided in half
1/4 cup parmesan cheese
1/2 cup water
Preheat oven to 350. Cook onions and mushrooms until soft, add garlic and cook one minute more. Add butter and melt. Add mushroom mixture to breadcrumbs, half of onion soup mix and parmesan cheese to make a stuffing. Lay one piece of steak on a cutting board and put 2 heaping spoons of stuffing on one end. Roll up and place seam side down in baking dish. Continue with all pieces of steak. If you have extra stuffing you can put it in the baking dish around the steak. Mix remaining onion soup mix with water and pour over steak. Cover and bake for 30 minutes.