Ingredients
1 tablespoon champagne vinegar
1 tablespoon grainy Dijon mustard
Coarse salt and freshly ground pepper
3 to 4 tablespoons extra-virgin olive oil
1/2 cup walnut halves, toasted and finely chopped
8 cipollini onions (about 4 ounces), peeled and halved if desired
1/2 cup balsamic vinegar
Coarse salt and freshly ground pepper
2 tablespoons unsalted butter
1 medium apple (preferably Golden Delicious), cored and cut into 1/2-inch-thick slices
8 slices French cooked ham or boiled ham
1 head Bibb or Boston lettuce, leaves separated
3 ounces Gruyere cheese, thinly sliced
8 slices rustic bread, for serving
Preparation
Make the dressing: Whisk champagne vinegar, mustard, and 1/2 teaspoon salt in a medium bowl. Gradually add oil, whisking until emulsified. Stir in walnuts. Season with pepper. Set aside.
Stir onions, balsamic vinegar, and 1/2 teaspoon salt in a skillet; season with pepper. Bring to a boil. Reduce to a simmer. Cook, stirring occasionally, until onions have absorbed most of the liquid, 8 to 10 minutes. Drain. Let onions cool.
Melt butter in a medium skillet over medium-high heat. Add apple; cook, flipping once, until just beginning to brown and soften, 1 to 3 minutes per side. Remove from heat; set aside.
To serve, arrange 2 slices of ham on each of 4 plates. Toss lettuce with dressing; divide among plates. Arrange cheese and apple slices on top, evenly dividing among plates. Garnish each plate with 2 onions. Serve with bread.
