Hot sandwiches with cheese, corned beef and sauerkraut

Ingredients:

• 1.5 tbsp unsalted butter + more as needed
• 1 small onion, thinly sliced
• 1 tbsp. sugar
• 3/4 cup dark beer (preferably porter)
• 30 g thin slices of corned beef, cut into strips
• 2 tsp Worcestershire sauce
• 1 tbsp. grainy mustard
• 1.5 tbsp. grated Jarlsberg cheese (about 170 g)
• 4 slices of marble rye bread
• 0.5 cups sauerkraut, washed

Preparation:

1. In a large skillet, melt 1/2 tablespoon of butter over medium-high heat. Add the onion and season with sugar, salt, and black pepper to taste. Cook, stirring occasionally, until the onion is soft and golden, about 10 minutes. Add the beer and continue cooking, stirring occasionally, until the onion is soft and the liquid has thickened, another 8 minutes. Remove from heat and stir in the corned beef, Worcestershire sauce, and mustard.
2. Divide half the cheese between two slices of bread, top with the corned beef mixture and the remaining cheese. Top the sandwiches with the remaining two slices of bread.
3. In a large skillet over medium heat, melt the remaining 1 tablespoon butter. Add the sandwiches and cook, pressing occasionally with a spatula, until the bread is toasted and the cheese is melted, about 4 minutes per side, adding more butter to the pan if necessary.
   
   Note
   
   Rinse the sauerkraut before adding it to prevent the sandwiches from being too salty.