Other mix-ins include sliced black olives, chopped fresh parsley, chopped fresh chives, walnut pieces, chopped dill pickles, and capers.
In a medium bowl, coarsely chop 8 peeled hard-cooked eggs.
Add 1/2 cup mayonnaise, 2 tablespoons chopped celery, 2 teaspoons Dijon mustard, and a few dashes of hot-pepper sauce (or more, if you like a spicier salad). Season to taste with salt and pepper; stir gently to combine. Serve with greens -- such as lettuce or watercress -- on bread or toast.