Apple Rum Burger Recipe

Form patties

Divide the 1 lb of grass-fed ground beef into three equal portions (about 1/3 lb each). Gently form each portion into a loose patty about 3/4 inch thick, making a shallow dimple in the center of each patty with your thumb to prevent doming while cooking. Do not overwork the meat.

Season both sides of each patty with kosher salt (about 1 tsp total) and freshly ground black pepper (about 1/2 tsp total). Brush a thin layer of neutral oil on the patties or on the grill/pan if desired. If using, lightly brush Worcestershire sauce on one side of each patty before cooking for added savory depth.

Preheat a cast-iron skillet or grill over medium-high heat until hot (about 5 minutes). If using a skillet, add 1 tsp neutral oil and swirl to coat. Cook patties 3–4 minutes per side for medium (internal temperature 145–150°F / 63–66°C), adjusting time for your preferred doneness. During the last 1 minute of cooking, place Wisco cheddar slices on each patty and cover the pan or close the grill to melt the cheese.

Remove patties from heat and tent with foil to rest for 3–4 minutes while you finish the relish and toast the buns.

Prepare aromatics and apple

Peel and thinly slice the yellow onion to yield about 1 cup. Core the Granny Smith apple and finely dice it to about 1 cup (peeling optional).

In a small skillet over medium heat, add 1 tsp olive oil and 1 tsp unsalted butter. When the butter foams, add the sliced onion and a pinch of salt (from the 1/4 tsp measurement). Cook, stirring occasionally, until the onion is softened and beginning to brown, about 6–8 minutes.

Add the diced apple and continue to cook 2–3 minutes until the apple starts to soften. Stir in 2 tablespoons dark rum, 1 tablespoon brown sugar, and 1 tablespoon apple cider vinegar. Increase heat briefly to bring the mixture to a gentle simmer so the rum deglazes the pan and the alcohol mostly cooks off, about 1 minute.

Reduce heat to low and stir in 1/2 tsp Dijon mustard, remaining 1/4 tsp salt (if needed), and 1/4 tsp freshly ground black pepper. Cook another 1–2 minutes until flavors meld and the relish is glossy but not wet. Remove from heat and let cool slightly. Taste and adjust seasoning with additional salt or vinegar if desired.

Toast the buns: Spread 1 tsp unsalted butter on cut sides of the split bun. Toast cut-side down in a skillet or on the grill over medium heat until golden brown, about 1–2 minutes.

If using mayonnaise, spread about 1 tsp on the bottom bun. Place a lettuce leaf on the bottom bun, then the tomato slices.

Place the rested, cheese-topped burger patty on the tomato. Spoon 1–2 generous tablespoons of the warm Sweet Onion Rum Relish over the cheese-topped patty.

Cap with the toasted top bun. Serve immediately, with extra relish on the side if desired.