Heat up 2 tbsp of extra virgin olive oil. Pan fry zucchini, lightly salting, 2-3 minutes each side. Set aside and pan fry leeks until soft, but not browned. Set aside
Place mixed salad greens in a bowl. To another bowl, add celery, scallions and parsley. Add a little salt and pepper to taste. Add 2 Tbsp olive oil, juice of 1/2 a lemon and 1 Tbsp balsamic to each bowl. Stir to coat with dressing.
Spread mixed salad greens on a serving plate. Over the top of the salad, add the celery, scallions and parsley mixture. Then, scatter the zucchini and leeks, then the pistachios across the top of the salad.