- 4 3×5-inch slices seeded rye bread
- Coarse-grained Dijon mustard with horseradish
- 4 ounces thinly sliced Swiss cheese
- 4 ounces thinly sliced Black Forest ham
- 4 teaspoons chopped fresh dill
- 1 egg
- 1 tablespoon unsalted butter
- Spread 1 side of each bread slice with mustard. Divide half of cheese and all of ham between 2 bread slices; top with remaining cheese. Tuck in cheese and ham around edges. Sprinkle each with 1/2 teaspoon dill. Top with remaining bread, mustard side down, to form sandwiches.
- Whisk egg and remaining 3 teaspoons dill in 9-inch pie dish. Brush both sides of sandwiches with egg mixture.
- Melt butter in medium skillet over medium heat. Add sandwiches; cover. Cook until sandwiches are golden and cheese melts, about 6 minutes per side. Cut in half diagonally and serve.