Stone and finely dice the dates. Squeeze the lemon.
For the dressing, mix a third of the dates with 3 tablespoons of lemon juice, oil and 4 tablespoons of water, puree to taste and season with salt and pepper. Wash and clean the fennel, remove the stalk. Chop the fennel greens. Halve the tubers and cut into very fine slices. Mix with the dressing.
Roughly chop the walnuts. Wash and halve the apples, remove the core and cut the apple halves into thin slices. Mix immediately with the salad and season everything with salt and lemon juice.
Wash the lettuce leaves and pat dry or spin dry. Arrange 2 leaves on each plate. Arrange the fennel salad on top and garnish with the remaining date cubes, the chopped walnuts and the fennel greens.