Firefly Smashburger Recipe

Slice and sweat shallots

Peel and thinly slice 3 shallots. In a medium skillet over medium heat, warm 1 tablespoon olive oil and 1 tablespoon butter until butter foams.

Add sliced shallots, sprinkle 1/2 teaspoon sugar, and a pinch of salt. Cook, stirring occasionally, until the shallots are soft and starting to brown, about 10–12 minutes. Reduce heat as needed to prevent burning.

When shallots are golden, add 1 teaspoon red wine vinegar to deglaze the pan, stir to combine, and cook 1 more minute. Season with 1/4 teaspoon kosher salt and 1/8 teaspoon ground black pepper. Remove from heat and set aside.

In a small bowl, whisk together 1/2 cup mayonnaise, 1 1/2 tablespoons sriracha, 1 teaspoon lemon juice, 1/2 teaspoon grated garlic, 1/4 teaspoon kosher salt, and 1/2 teaspoon honey (if using).

Taste and adjust: add more sriracha for heat or more honey for sweetness. Cover and refrigerate until ready to assemble.

Form patties

Divide 1 lb 80/20 ground beef into two equal portions (about 8 ounces each). Gently form into loose 4-inch patties about 3/4 inch thick, making a shallow depression in the center of each patty with your thumb (this helps prevent doming). Do not overwork the meat.

Season both sides of each patty with 1/2 teaspoon kosher salt and 1/4 teaspoon freshly ground black pepper (total 1 tsp salt and 1/2 tsp pepper across both patties).

Cook patties

Heat a heavy skillet or cast-iron pan over medium-high until very hot. Add 1 tablespoon butter and let it melt and foam. Place the patties in the pan and cook without moving for 3 minutes to develop a crust. Flip and cook 2–3 more minutes for medium (adjust 1–2 minutes for rarer or longer for well done).

During the last 30–45 seconds of cooking, place two slices of American cheese on each patty. Cover the pan with a lid or tent with foil to melt the cheese quickly, about 30–45 seconds.

Transfer cooked patties to a plate and tent loosely with foil to rest for 2 minutes.

While patties cook, spread 1 tablespoon butter on the cut sides of 2 brioche buns. In a separate skillet or the same pan (if room), toast the buns buttered-side down over medium heat until golden and crisp, about 1–2 minutes. Remove from heat.

To assemble: spread about 1 tablespoon sriracha aioli on the bottom half of each toasted bun. Place lettuce leaf (if using) on aioli, then the cheeseburger patty. Top each patty with a generous portion of caramelized shallots (about half the shallots per burger). Add pickles if desired.

Spread a thin layer of aioli on the top bun, cap the burger, and press gently. Serve immediately.