Ingredients

  • 1 onion, cut into paper-thin slices
  • 2 1/2 teaspoons grainy Dijon mustard
  • 2 teaspoons red- or white-wine vinegar
  • 1/4 teaspoon salt
  • 1/4 teaspoon fresh-ground black pepper
  • 1/2 cup olive oil
  • 1 pound sliced smoked ham, such as Black Forest, cut into matchstick strips
  • 1/2 pound sliced Gruyere cheese, cut into matchstick strips
  • 3/4 cup chopped fresh parsley

Method

  • Put the onion in a small bowl of cold water and let stand for 10 minutes.
  • Drain the onion, rinse, and then pat dry with paper towels.
  • Meanwhile, in a large glass or stainless-steel bowl, whisk together the mustard, vinegar, salt, and pepper.
  • Add the oil slowly, whisking.
  • Add the ham, cheese, onion, and parsley to the vinaigrette and toss.