Preheat the oven to 250°F or prepare a food dehydrator. Line two large rimmed baking sheets with parchment paper.
Destem kale. Wash and dry leaves thoroughly. Tear leaves into bite-size pieces and spread on baking sheets.
Whisk together nutritional yeast, tahini, lemon juice, vinegar, tamari, olive oil, garlic granules, mustard, salt, pepper and roasted garlic, if using, in a medium bowl until thoroughly combined.
Spoon tahini mixture over kale. Massage the mixture into the kale, making sure all leaves are evenly coated. Spread them in a single layer, so they bake as evenly as possible.
Bake until kale is crisp and tahini mixture is dry, 50 to 70 minutes, turning and tossing leaves halfway through. Baking time will vary depending on the amount of kale, how the leaves are coated and how much room they have on the baking sheets.
If using a food dehydrator, place kale on the stackable layers. Dehydrate until kale is crisp.
Cool kale chips completely before storing in an airtight container