The secret to making a perfect grilled cheese sandwich is cooking it over low heat, which brings out the subtle flavors of a cheese, and slathering the bread with butter, which crisps it in the pan. Comté, with its semifirm texture and nutty taste, is great for grilling.
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.