Place chickpeas in a large bowl and sprinkle with baking soda then cover with water. Soak overnight or for 12 hours; drain.
Place chickpeas in a high-speed food processor and pulse until grainy, remove and set aside.
Add onion, garlic, parsley and cilantro to the food processor and pulse until smooth. Pour chickpeas back into the food processor and add all remaining ingredients (salt through cayenne.) Pulse until everything is evenly incorporated. Be sure to use a rubber spatula to scape down the sides at least once.
Remove mixture from the food processor and place in a bowl. Cover with plastic wrap and refrigerate at least once hour.
When you're ready to fry the falafel, heat oil in a large, deep skillet over high heat. Form falafel mixture into small patties (I like to use a cookie scoop to start) then place in the hot oil. Cook until golden brown on both sides, about 5-6 minutes total flipping once. Remove from oil and place on a plate lined with paper towel then sprinkle with salt while it's still hot.
Serve in pita bread with tahini sauce, tomato and onion if you wish.
Tahini Sauce
Whisk all ingredients in a small bowl then thin with warm water, one tablespoon at a time, until you reach desired consistency.
Notes
Nutrition facts will vary based on the quantity of oil absorbed while frying. To reduce the calorie count simply reduce the amount of oil you use to fry. For these nutrition facts I use 1 cup of oil absorbed into the falafels.