Grilled Taleggio Sandwich with Tomato and Basil

Arrange bread in a single layer on a clean work surface. Stir together butter and mayonnaise. Spread mixture evenly onto one side of every slice (1 scant tablespoon per slice).

Heat a large skillet, preferably cast iron, over medium. Flip over 4 slices on work surface (so they're plain-side up); divide Taleggio among them. Top each with a tomato slice; season generously with salt and pepper. Place 2 basil leaves on top of each. Carefully sandwich together.

Place sandwiches in skillet (in two batches, if needed). Reduce heat to medium-low; gently top sandwiches with a lid slightly smaller than skillet for even cooking. Cook, flipping once halfway through, until crisp and golden on both sides and cheese is melted, 7 to 9 minutes. Serve immediately.