Cut avocado in half lengthwise, then peel and pit. Turn halves cut side down, then cut each half crosswise into thin slices. With a wide spatula, transfer each avocado half to a dinner plate, keeping slices together. With your fingers, gently pull slices into a loose S that fills the center of the plate.
Mix crab gently with Louis dressing. Add salt and pepper to taste.
Mix salad leaves with vinegar, oil, and salt and pepper to taste.
Lay 2 endive leaves parallel at the tip of each avocado S. Spoon crab mixture beneath the endive and next to the avocado, then mound salad leaves onto base of endive. Scatter plates with the diced bell pepper.
Mince egg in a food processor, or rub through a fine strainer. Sprinkle over crab salad.
Nutritional analysis per serving without dressing.