- 1 1/2 tbsp unsalted butter, plus more if needed
- 1 small onion, thinly sliced
- 1 tbsp sugar
- Kosher salt and freshly ground pepper
- 3/4 c dark beer (preferably porter)
- 2 oz deli-sliced corned beef, cut into strips
- 2 tsp Worcestershire sauce
- 1 tbsp whole-grain mustard
- 1 1/2 c grated Jarlsberg cheese
- 4 slices marble rye bread
Melt 1/2 tablespoon butter in a large skillet over medium-high
heat. Add the onion and sprinkle with the sugar, 1/2 teaspoon salt, and
pepper to taste. Cook, stirring occasionally, until soft and golden,
about 10 minutes. Add the beer and continue cooking, stirring
occasionally, until the onions are tender and the liquid is slightly
syrupy, about 8 more minutes. Remove from the heat and stir in the
corned beef, Worcestershire sauce and mustard.
Divide half of the cheese between 2 bread slices; top with the corned beef mixture, and the remaining cheese and 2 bread slices.
Melt the remaining 1 tablespoon butter in a large skillet over medium heat. Add the sandwiches and cook, pressing occasionally with a spatula, until the bread is toasted and the cheese melts, about 4 minutes per side, adding more butter to the pan if needed.
Divide half of the cheese between 2 bread slices; top with the corned beef mixture, and the remaining cheese and 2 bread slices.
Melt the remaining 1 tablespoon butter in a large skillet over medium heat. Add the sandwiches and cook, pressing occasionally with a spatula, until the bread is toasted and the cheese melts, about 4 minutes per side, adding more butter to the pan if needed.
