1Shape sirloin into 4 patties. Heat large skillet over medium-high heat and spray with cooking spray. Add patties and cook until done.
2In a medium skillet over medium-high heat the olive oil. Add the onions, mushrooms, salt and pepper and saute until veggies are tender crisp. Add flour and stir for 1 minute. Add the beef broth and cook until thickened, about 30 seconds. Remove veggies from pan and keep warm.
3Wipe skillet clean. Coat 1 side of each rye bread slice with cooking spray and add 4 slices and brown. Top each slice with a pattie, provolone and veggie mixture. Top with remaining rye bread slice, turn and cook until bread is browned.