Cut lettuce, romaine, and endive in quarter-inch strips. Remove seeds and white portions from green peppers; cut in two lengthwise, then cut in very thin slices crosswise. Break watercress in pieces. Mix ingredients, and toss lightly into salad bowl. If desired, garnish with sections of grapefruit, slices or sections of tomato, or slices of cucumber. Serve with ChifTonade or Chili Dressing.