01 -
Spread softened salted butter generously over one side of each bread slice. Grate the gruyere and gouda cheeses; crumble the goat cheese.
02 -
Place two bread slices, buttered side down, on a work surface. Evenly distribute 1/2 cup grated gruyere over each slice. Sprinkle 2 tablespoons crumbled goat cheese atop the gruyere. Add 1/4 cup grated gouda to each. Layer 1 to 1 1/2 slices of medium cheddar over the gouda, tearing slices if needed to create a complete cheese layer.
03 -
Position the remaining bread slices on top, buttered side facing up, to close the sandwiches. Preheat a cast-iron or heavy skillet over medium-low heat.
04 -
Set the assembled sandwiches in the preheated skillet. Cook for 4 to 5 minutes, pressing gently with a spatula, until the bottoms are golden brown and the gruyere begins to melt.
05 -
Flip the sandwiches and cook an additional 4 to 5 minutes until the second side is golden and all cheese is fully melted. Transfer to a cutting board, slice, and serve warm.