In a small bowl whisk together lemon juice, mustard, shallot, parsley, basil, salt and pepper to taste; set aside.
Put just-cooked potatoes in medium bowl, toss with 3 tablespoons dressing and salt and pepper to taste; set aside.
Place large lettuce leaves side by side in a circle around a large serving platter so the leaf tops extend just beyond the rim.
In a large bowl, mix spinach with 2 tablespoons dressing. Create a bed of spinach on platter, leaving a frilly-edged frame of lettuce leaves exposed.
Put navy beans in empty bowl and use the back of a large spoon to smash some. Add celery, lemon zest, 3 to 4 tablespoons dressing, salt and pepper to taste, and mix, Mound the beans in the center the platter, on top of the spinach.
Mound potatoes on one-quarter of the platter to the left of navy beans. Then arrange tomato wedges in adjacent quadrant.
Put green beans, 2 tablespoons dressing, and salt and pepper taste in the bowl; mix and mound the dressed green beans in the third quadrant.
Arrange the eggs and olives in remaining quadrant. Sprinkle entire salad with capers. Serve immediately.