Brisket Grilled Cheese Sandwich Recipe

Warm and season brisket

Place the thinly sliced smoked brisket in a medium skillet over medium-low heat. Add the beef au jus (about 60 ml), yellow mustard, Worcestershire sauce, and black pepper. Stir gently to coat the brisket and heat for 3–5 minutes until warmed through and most of the liquid is absorbed but the meat remains moist. Remove from heat and keep covered so it stays warm while assembling sandwiches.

If using caramelized onions, heat 1 tablespoon olive oil in a small skillet over medium heat. Add the thinly sliced onion and 1 teaspoon salt. Cook, stirring occasionally, until soft and deep golden, about 10–15 minutes. Add 1 teaspoon brown sugar in the last 2 minutes if using to speed browning. Transfer onions to a bowl and set aside.

Lay out 4 slices of bread, buttered side down. Evenly divide half of the grated cheddar across the 4 slices (about 1/2 cup cheddar per sandwich base).

Top the cheddar with an even portion of the warmed brisket (about 1/2 cup brisket per sandwich). If desired, place 2 dill pickle slices and about 2 tablespoons caramelized onions over the brisket.

Sprinkle an even layer of shredded mozzarella and the remaining cheddar over each sandwich (about 1/2 cup combined cheese per sandwich). Top with the remaining bread slices, buttered side up.

Heat a large skillet or griddle over medium-low to medium heat. Place assembled sandwiches in the skillet (work in batches if necessary). Cook 3–4 minutes on the first side, pressing gently with a spatula or heavy pan, until the bread is golden brown and the cheese begins to melt.

Carefully flip each sandwich and cook another 3–4 minutes on the second side, pressing occasionally, until the second side is golden brown and the cheese is fully melted. If the bread is browning too quickly before the cheese melts, lower the heat and cover the pan for 1–2 minutes to trap heat and melt the cheese.

Remove sandwiches to a cutting board and rest 1 minute. Slice each sandwich in half diagonally and serve immediately.