Combine ground beef, Worcestershire sauce, egg, salt, and pepper in a mixing bowl and mix. Mix it fast but mix it thoroughly.
Shape the patties as quickly as you can and lay them out on a parchment paper covered metal tray.Note: Divide into 4 qual weight portions if you’re making 1/2-lb burgers or 6 equal portions if you’d rather make 1/3-lb burgers.
Season each patty with some more salt and pepper on both sides and cover the tray with plastic wrap.
Refrigerate for 2-4 hours before cooking. (If you need to, you can refrigerate overnight but make sure to cover the tray with plastic wrap air-tight.)
Sauce:
Preheat the cooking pan over medium to medium-low heat and add oil and butter. Let butter melt and add sliced onions. Sauté onions until they start to get golden brown.
Sprinkle flour over the onions and stir to coat them evenly.
Start to slowly pour in whiskey as you stir the onions. It will start to gently simmer and thicken.
Slowly pour in beef stock as you stir. Once combined, stir in Worcestershire sauce and tomato paste. Stir it in until all combined.
Season with salt and pepper and add bay leaf. Let the sauce gently simmer over medium-low heat for a few minutes. Take off heat.
Sauteed Mushrooms:
Preheat the cooking pan over medium to medium-low heatand add oil and butter. Let butter melt and add sliced mushrooms. Season with salt and pepper and sauté until they get golden brown. Take out and set aside.
Cooking the burgers:
Use your fingers to make a well in the center of each patty, about half way deep, before taking off the plastic wrap.
Preheat a cooking pan over medium and add some oil. The pan should be hot when adding the burgers.
Add burger patties and cook for 5-8 minutes per side, depending on how well you want them*. Do not disturb the burgers while cooking. Pour in whiskey about half way through the cook, after you flip the patties.(Note that these are 1/2 lb. patties, they will take a couple minutes longer than thin burgers to cook.)
Take cooked patties out of the pan as soon as they are done, and let them rest on the plate for about 5 minutes before servings. Tent them loosely with a sheet of aluminum foil to keep warm.
Assemble:
Top the burger off with sauteed mushrooms and onions, bacon and whiskey sauce.
Notes
*Burger Temperature: For medium-rare burgers – 130°-135° For medium – 140°-145° For medium well – 150°-155° For well done – 160°-165°
Cooking burgers: These patties are 8 oz. so smaller and thinner burgers will have a slightly different temperature. But it’s important to note that burgers cook very fast, so even 1 minute will make a difference. Lucky for you, this recipe produces delicious and juicy burgers even if you cook them to medium well.
Do not disturb: when cooking, do not touch the burgers again until ready to flip. Fight the urge to readjust or move them around.
Do not press: for the love of everything that is good and pure, do not press the burgers. It breaks my heart to see people squeezing all those wonderful meat juices out.
Let it rest: when done, take them off the grill and let them rest for a few minutes before eating. This will give a chance for all the juices that have compressed during the cooking process to spread out and give you a nice juicy bite every time.