Begin by heating 1 tablespoon of salted butter in a skillet over medium heat. Allow the butter to melt completely until it becomes bubbly and lightly foamy.

Place one slice of sourdough bread into the skillet, allowing it to soak up some of that rich, melted butter. Layer half of the Muenster cheese evenly over the bread, then spread the well-fermented kimchi over the cheese.

Sprinkle sugar, fish sauce, gochugaru, and beef stock powder over the kimchi to enhance its flavor profile. Ensure each ingredient is well-dispersed.

Top with the remaining Muenster cheese, then carefully place the second slice of sourdough on top. Gently press down on the sandwich.

Let your sandwich grill for about 3–4 minutes or until the bottom is golden brown and crispy. Flip the sandwich carefully with a spatula to cook the other side.

Add the remaining tablespoon of butter to the skillet before grilling the other side. Cook for an additional 3–4 minutes until the cheese is fully melted.

Once both sides are perfectly grilled, remove your sandwich from the skillet and let it cool for a moment. Slice it in half and serve warm.