Fit your food processor with a slicing blade and cut cabbage and red pepper using it.
Wash and scrub all the vegetables well but do not peel. Remove the ends from beets and carrots. Then switch to a large grating blade and process the rest of the vegetables. Alternatively you can use a sharp knife to cut the cabbage and red pepper and a vegetable grater for the rest.
Chop cilantro and combine all vegetables in a large bowl.
In a jam jar combine all the dressing ingredients but the water and shake vigorously to combine. Add water 2 tbsp at a time to achieve a desired consistency.
Add half of the lemon garlic tahini dressing to the slaw and toss gently to coat. Salt to taste. Sprinkle with sesame seeds. (Keep the remaining dressing in a fridge for another use.)