Form 4 thick patties with the ground sirloin. Spray a cast iron skillet with PAM or an oil spray. On med-high heat sear the patties in hot skillet, turning once.
While patties are searing mix the cream of mushroom soup with 3/4 can of water, stir in fresh mushrooms.
Pour soup mixture over patties while on med-high heat. The soup will bubble. Cover with foil and place in a preheated oven of 400 degree and bake for 45 minutes. Take of the foil the last 15 minutes to brown. If gravy is too thick, add additional water and if not thick enough, cover and increase temp to 425.
In the last 5 minutes of baking, French's crispy onions can be added for a topping. I have also added cut potatoes to cook with the burger patties as a meal in one.