Put the beans in a large bowl and cover with water. They will expand. Soak for 24 hours, adding water if needed to keep beans covered.
Drain beans well and transfer to a food processor.
Add remaining ingredients except for oil. Pulse until well chopped. Scrape down sides of bowl and pulse again. Taste and adjust spices (can add up to 1 Tbs. more chickpea flour if needed to form ball.)
Put the oil in a large pot, 2 inches deep. Turn heat to medium-high and heat oil until it shimmers. Make balls with the batter, 1 inch in diameter.
Fry one as a tester and taste. Add more salt or cumin if necessary. Continue frying a few at a time, until golden brown.
Drain on paper towel.
For the tahini sauce, process all of the ingredients in a food processor or hand mill.
Recipe by iEatGreen at https://www.ieatgreen.com/recipe-falafel-with-tahini-sauce/