Zelda's Burger Recipe

Form patties

Place the ground sirloin in a bowl. Add Worcestershire sauce, salt, and black pepper. Gently mix with your hands until just combined — do not overwork. Divide into 4 equal portions and form into patties about 3/4 inch thick, making a slight indentation in the center of each so they cook evenly.

Cook patties

Heat a heavy skillet or cast-iron pan over medium-high heat until very hot. Add 1 tsp vegetable oil and swirl. Add patties (do not overcrowd; cook in batches if needed). Cook 3 to 4 minutes on the first side without moving to develop a crust. Flip and cook 2 to 3 minutes for medium-rare to medium, or longer to desired doneness. In the last 1 minute of cooking, place one slice of aged cheddar on each patty, cover the pan with a lid or tent with foil to melt the cheese. Remove patties to a plate and let rest for 3–4 minutes.

Prepare vegetables

While the patties come to room temperature, thinly slice the onion and roughly slice the mushrooms.

Sauté mushrooms and onions

In a large skillet over medium heat, add 1 tbsp olive oil and 2 tbsp butter. Once the butter foams, add the sliced onion and cook, stirring occasionally, until soft and beginning to brown, about 6–8 minutes. Add the mushrooms and continue to cook until the mushrooms release their liquid and it evaporates and both mushrooms and onions are deeply golden, about 6–8 more minutes. Season with 1/2 tsp salt, 1/4 tsp pepper, and 1 tsp fresh thyme leaves (if using). Stir to combine and remove from heat. Keep warm.

Toast brioche buns

Slice the brioche buns in half. In a clean skillet over medium heat, melt 2 tbsp butter. Place cut sides of buns down and toast until golden brown, about 1–2 minutes. Remove and set aside.

Spread mayonnaise on the bottom bun and Dijon mustard on the top bun if using. Place a handful of arugula or lettuce on the bottom bun. Lay a cheddar-topped sirloin patty on the greens, spoon a generous portion of the sautéed mushrooms and onions over the cheese, and cap with the toasted top bun. Repeat for remaining burgers.

Serve immediately while hot. Recommended sides: fries, potato chips, or a light salad.