Step 1

Heat a 10-inch cast-iron skillet over medium. Stir together preserves and capers in a small bowl, lightly smashing capers. Spread butter on one side of each bread slice, and place slices, buttered sides down, on a work surface. Top 2 bread slices evenly with Taleggio slices. Top remaining 2 bread slices with preserves mixture, and top evenly with grated Gruyère. Close sandwiches, buttered sides out, pressing to flatten.

Step 2

Cook sandwiches in hot skillet until bread is golden on the outside and cheese is melted, about 3 minutes per side. Transfer sandwiches to plates; serve immediately.