Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1 1/2  tablespoons   red wine vinegar
   1 1/2  tablespoons   Dijon mustard
   1      tablespoon    water
                        salt -- to taste
                        pepper -- to taste
     1/4  cup           chopped onion
   1 1/2  tablespoons   capers
   1      large         ripe tomato -- diced
   1      pound         salmon steaks - 3/4-inch thick
   2      teaspoons     olive oil

Preparation:

In a small bowl, combine vinegar, mustard, water, and salt if desired. Add onion, capers, and tomato, mix well, cover, and set aside. Brush salmon lightly with oil, sprinkle with salt and pepper, and broil or barbecue, turning once, about 4 minutes on each side or until fish flakes easily. Serve immediately, topped with the tomato relish.