Middle Eastern Salad

Name: Middle Eastern Salad
Ingredients: 3 small vine ripened tomatoes, seeded and finely diced; 2 small Persian cucumbers, seeded and finely diced; 1 medium red bell pepper, seeded and finely diced; 1 medium zucchini, seeded and finely diced; 1 scallion, trimmed and thinly sliced; ½ cup fresh flat leaf parsley leaves, finely chopped; ¼ cup fresh mint leaves, finely chopped; Pinch of sumac to top; Grain-free pita chips or tortilla chips to serve (optional).; 1 Tablespoon/15ml fresh lemon juice (plus more for whipped tahini); 2 Tablespoons/30ml extra-virgin olive oil; ½ teaspoon fine sea salt; ½ cup/120ml tahini; 2 Tablespoons/30ml fresh lemon juice; 1 small garlic clove; ¼ teaspoon fine sea salt; 1/8th teaspoon ground coriander; ¼ cup/60ml filtered water