Salad Nicoise

Ingredients

• ¼ cup red-wine vinegar
• 1 tablespoon Dijon mustard
• 1 teaspoon dry mustard (mustard powder)
• Salt and freshly ground black pepper, to taste
• ¾ cup olive oil
• 1 tablespoon chopped fresh herbs (any combination of chervil, parsley, chives, tarragon, and marjoram)
• 1 head oak leaf lettuce, washed and dried
• 1 head red leaf lettuce, washed and dried
• ¼ pound green beans, stem-ends trimmed, cooked
• ¼ pound yellow beans (wax beans), stem-ends trimmed, cooked
• 24 cherry tomatoes
• 4 hard-boiled eggs, shelled and halved
• 12 cooked new potatoes, halved
• ½ small red onion, thinly sliced
• 2 (7-ounce) cans Italian-style tuna fish packed in oil, drained
• 2 tablespoons capers, washed and drained
• 8 oil-packed anchovy fillets, drained and patted dry