To dehydrate kale in the oven, preheat it at the lowest temperature setting it has. Mine is 150 degrees F, but many modern stoves have warm settings that are as low as 110 degrees F.
Rinse the kale and remove it from the stem. Rip the leaves into bite size pieces and place them on a baking sheet. Sprinkle with sea salt and place them in the center of the oven.
Leave the oven door open and use a fan to circulate the air even better (place it pointing into the oven). Let them sit until they are your desired crispiness. Mine took about two and a half hours.
When the chips are dried out and crispy, pull them out of the oven and drizzle them with olive oil. Carefully, very carefully, toss the chips around with your hands to coat them with oil. Sprinkle with as much nutritional yeast and you would like and fluff them again. Transfer to a bowl or zip lock bag.
Notes
Makes about 5 or 6 cups of chips depending on the size of the bunch of kale.