For the dressing, combine the yogurt, lemon zest and half the lemon juice, anchovy paste, Worcestershire sauce, dill, garlic, parmesan, and olive oil. Stir together until smooth and creamy. Taste, and add a little more olive oil if you'd like a thinner dressing, lemon juice for more tang, and salt to taste. If the dressing tastes very tart from the yogurt you might need a little more salt than you think.