01 -
In a metal mixing bowl, combine ground beef, 1 tablespoon Worcestershire sauce, egg, salt, and pepper. Mix quickly and thoroughly.
02 -
Shape mixture into four equal portions for 1/2-pound burgers or six portions for 1/3-pound burgers. Lay patties on a parchment-lined metal tray. Season both sides with additional salt and pepper. Cover with plastic wrap.
03 -
Refrigerate patties for 2 to 4 hours. Ensure an airtight cover if refrigerating overnight.
04 -
Preheat a cooking pan over medium to medium-low heat. Add oil and butter. When butter melts, add onions and sauté until golden brown. Sprinkle flour, stirring to coat. Gradually pour in whiskey, allowing mixture to simmer and thicken. Add beef stock while stirring. Mix in Worcestershire sauce and tomato paste. Season with salt, pepper, and add bay leaf. Simmer for several minutes, then remove from heat.
05 -
Preheat a separate pan over medium to medium-low heat. Add oil and butter. Once butter is melted, add sliced mushrooms, season with salt and pepper, and sauté until golden brown. Set aside.
06 -
Press a shallow well in the center of each patty with your fingers. Preheat a large pan over medium heat and add oil. Once pan is hot, add patties and cook for 5–8 minutes per side to desired doneness. Flip patties after initial side is browned; pour 2 tablespoons whiskey into the pan halfway through cooking. Do not disturb burgers while they cook.
07 -
Transfer cooked patties to a plate, cover loosely with aluminum foil, and allow to rest for 5 minutes.
08 -
Place each patty on a hamburger bun, top with whiskey sauce, sautéed mushrooms, and bacon. Serve immediately.