Make 4 super thin patties using ground CHUCK. On one grill pan cook the onions, mushrooms, and jalapeno slices. On another grill pan cook the patties and bacon.
Cook each patty about 7 min per side on a good hot grill with a med-high heat. Flip once. When patties are done to your likeness, place cheese on top to melt.
Stack your burger using 1 pattie and all the trimmings. Add A-1 on top.
NOTE: to get a flame broiled taste, use ground chuck, the grease will drip onto the fire, the fire will flare up and you will get the smoky flame broiled flavor that is to die for and you don't need any seasoning! (I still like black pepper though). Happy eating.