step 1.
Prepare the patties: In a large mixing bowl, combine the ground beef, salt, and pepper. Gently mix and form into 4 patties about ¾ inch thick. Make a small indentation in the center of each patty. Preheat your grill or skillet over medium-high heat.
step 2.
Prepare toppings and sauce: Slice the tomato and red onion. In a small bowl, mix mayonnaise, ketchup, and mustard for the burger sauce.
step 3.
Cook the burgers: Grill or cook the patties for 4-5 minutes on each side for medium doneness. Add a slice of smoked Gouda cheese on each burger during the last minute of cooking. Remove from heat and let rest for 3 minutes. While resting, lightly toast the buns if desired.
step 4.
Assemble and serve: Spread burger sauce on the bottom bun, add a lettuce leaf, the burger patty with melted cheese, tomato slice, and red onion. Top with the other half of the bun and serve immediately.
step 5.
Storage (if needed): Wrap cooled burgers individually and refrigerate for up to 2 days. Reheat in a 350°F (175°C) oven for about 10 minutes. Store buns and toppings separately; assemble just before serving.
