Drizzle kale with olive oil and mix until coated. I have a can of olive oil spray- it works really well and you don't use as much oil. You can buy it at most grocery stores. Make sure there is 100% olive oil in the can, no other ingredients. It may have flavoring added that you like but that's up to you- I like the pure olive oil because I can then add my own extra flavoring like hot pepper flakes or black truffle salt for seasoning.
Bake for 1 hour or until lightly browned and crispy. Season with sea salt.