Prep Time: 10 min. • Cook Time: 4 min.
Divide ground beef into 8 equal balls about the size of a ping-pong ball (3-ounces each); refrigerate.
In a small mixing bowl, whisk mayonnaise, mustard, grated onion, hot sauce and Worcestershire to create a special sauce; refrigerate.
Using either a large cast iron griddle or 2 large cast iron pans heated to high, toast buns with butter; reserve to plates.
Space beef balls on hot cooking surface. Using a large metal spatula, smash each ball to ¼-inch-thick patties. (Tips: using the handle of a second spatula to push down on the top of the spatula adds leverage. Using parchment helps avoid spatula sticking to beef.)
Season patties with 1 teaspoon of reserved special sauce per patty; salt and pepper. Sear 2-3 minutes or until some fat begins to bubble up in center of patty. Quickly flip and top 4 of the patties with a slice of cheese. Sear another minute and place a plain patty atop a cheese patty; remove from cooking surface.
Build burgers with a smear of special sauce on bottom bun followed by shredded lettuce, tomato, double burgers and top bun.
Approximate Nutritional Information (Per serving):
Calories 790, Fat 57g, Sat Fat 20g, Trans Fat 1.5g, Cholesterol 160mg, Sodium 1980mg, Total Carbohydrate 27g, Fiber 1g, Sugars 6g, Protein 41g
ALLERGEN INFORMATION: Tree Nut-Free, Peanut-Free