4 tbsp. unsalted butter, softened
4 1⁄2"-thick slices sourdough bread
1 8-oz. piece comté cheese, grated
1. Spread butter evenly on both sides of each slice of bread. Put half the cheese on one slice and half on another. Top each with remaining bread slices. Heat a 12" cast-iron skillet over medium-low heat.
2. Add sandwiches to skillet and cook, flipping once with a metal spatula, until golden brown and crusty on both sides, 18–20 minutes. Transfer sandwiches to a cutting board and slice in half with a knife. Serve warm.