1.Make green tahini. Stir all ingredients until smooth; season to taste. Add a little water, if mixture is too thick.
2.Heat the oil in a large non-stick frying pan over low heat; cook sweet potato, turning, for 8 minutes or until tender.
3.Place avocado and juice in a small bowl; toss to coat, drain.
4.Divide avocado, sweet potato, turkey, tomato, carrot, cucumber and onion into lettuce leaves. Drizzle with green tahini and roll lettuce around fillings to enclose, just before serving.
You will need about 1 or 2 baby cos lettuces, depending on their size.Note