Classic Grilled Cheese

Spread 1 side of each bread slice evenly with mayonnaise. Place 1 bread slice, mayonnaise side down, on a sheet of parchment paper or wax paper. Top with American cheese slices and shredded Cheddar cheese. Cover with remaining bread slice, mayonnaise side up. Place a second sheet of parchment paper or wax paper on top of sandwich, and press gently.

Heat a large cast-iron skillet over medium. Remove sandwich from bottom piece of parchment paper, leaving top piece in place, and transfer to hot skillet. Place a small, heavy skillet on top of sandwich, and press. Cook until cheese melts and bread is golden brown on bottom, about 2 minutes. Remove small skillet; turn sandwich, and cook, without pressing, until golden brown on bottom, about 2 minutes.Caramelized Onion Grilled Cheese: Prepare recipe as directed, substituting 2 oz. (1/2 cup) shredded fontina cheese, 1 oz. (2 Tbsp.) creamy goat cheese, and 1/4 cup caramelized yellow onion (from 1/2 cup sliced onion) for American cheese slices and shredded sharp Cheddar cheese.Ham and Dijon Grilled Cheese: Prepare recipe as directed, substituting 2 oz. (1/2 cup) shredded Gruyère cheese, 2 oz. sliced deli ham, and 1 Tbsp. Dijon mustard for American cheese slices and shredded sharp Cheddar cheese.Brie, Fig, and Arugula Grilled Cheese: Prepare recipe as directed, substituting 2 oz. thinly sliced Brie, 1 1/2 Tbsp. fig preserves, and 1/4 cup loosely packed arugula for American cheese slices and shredded sharp Cheddar cheese.