In small mixing bowl, combine one tablespoon mayonnaise, lemon juice, and cracked black pepper. Add apples, grapes, celery slices, and walnuts; toss to thoroughly combine.
Spread remaining mayonnaise on outsides of bread slices. Place 2 slices of Wisconsin Gouda Cheese on each bread slice. Divide apple mixture between the 2 bread slices over Gouda. Place a slice of Gouda on top of the apple mixture on each slice.
Heat small skillet over low heat. Melt butter, coating skillet bottom, and grill each slice, mayonnaise-side-down, for about 4-5 minutes, or until cheese begins to melt (you may cover skillet to heat cheese faster).
Using spatula, transfer each side to a serving plate. Top each with a few celery leaves and press slices together.
- 2 tablespoons mayonnaise, divided
- 1/2 teaspoon fresh lemon juice
- Couple of turns of black pepper
- 1/4 Granny Smith apple, thinly sliced
- 1/4 Red Delicious apple, thinly sliced
- 3 red seedless grapes, halved
- 3 green seedless grapes, halved
- 1 tablespoon celery, sliced very thin, plus a few celery leaves
- 1 tablespoon walnut pieces, toasted
- 6 slices Wisconsin Gouda cheese
- 2 slices sourdough bread
- 1/2 tablespoon butter