Place the walnuts, almonds and sesame seeds in a bowl. Fill with water, then cover and chill in the refrigerator for 12 hours. Once complete, strain and rinse.
Add cilantro, parsley, olive oil, lemon juice, mint leaves, cumin, nutritional yeast, oregano, garlic, cayenne pepper, salt and ground pepper to the bowl of a food processor. Pulse mixture until smooth.
Add the soaked nut and seed mixture. Pulse until the nuts are the size of the sesame seeds.
Using 2 tablespoons at a time, roll the dough into balls. Press and rotate as you go to get the mixture to stick together.
Place the falafel on food dehydrator racks. Dehydrate at 110F for 10 hours, rotating halfway through. If you do not have a dehydrator, recipe can be cooked at the lowest temperature your oven will go (180F) for 3 hours, rotating halfway through.