1. To prepare the dressing, in a small bowl, whisk the tahini, yogurt, lemon juice, oil, garlic, salt, and water together.
2. In a medium bowl, combine the tomatoes, cucumber, parsley, mint and onion. Drizzle with the dressing; toss to coat.
3. To assemble the wraps, soften the tortillas according to package directions. Divide the salad among the tortillas. Fold up the bottom edge of each tortilla, then the left and right sides to enclose the filling.