Make the vinaigrette: In a bowl or a jar, combine the ingredients for the dressing. Whisk or shake to combine. Taste and adjust seasonings as needed and add more or less water to thin out the dressing.
Assemble salad: To a large bowl, add a bed of greens and drizzle some dressing. Toss to coat then top the salad with tomatoes, cucumber, onions and falafel.Add toppings: Sprinkle with olives, chopped parsley and drizzle with more dressing. Season with salt and black pepper, to taste.
Transfer to serving bowls: Divide into salad bowls and serve with with more dressing and hummus.