Divide the ground beef into two pieces and smash each one flat with hands until its very thin, about a 5 inch patty. place them on waxed paper then sprinkle with salt and pepper. Store in the fridge for at least an hour until ready to cook.
Prepare the sauce by mixing the mayonnaise and the Sriracha sauce together in a small mixing bowl. Set aside.
Toast the bread in a toaster until golden brown, Rub one side of each slice of bread with 1/2 tablespoon softened butter. Put butter sides together and set aside.
Heat a large nonstick skillet to medium high. Add the last 2 tablespoons of the butter and melt. When hot add the mushrooms and saute until tender. Lower heat to warm just to keep the mushrooms from getting cold.
Add the ground beef patties to the skillet and let cook for one or two minutes then flip over to cook the other side. After a short time and the ground beef is mostly cooked through, flip once more, and add the mushrooms then a slice of Swiss cheese to one patty and an American slice to the other pattie. Cover saute pan to help melt the cheese.
Spread Frisco sauce to each buttered-side piece of bread. Stack the patties with the American cheese patty on top then stack on the bottom slice of bread. Cut sandwich diagonal and serve with chips or fries.
Serving Size 1 sandwich
Servings 0