You can use the roasted/toasted just make sure the ingredients say 100% roasted/toasted seaweed,, no additives, if you still have second doubts take a small piece of nori and put it in a glass of water,,do you see any oily film on top,, you souldnt! Im half/Japanese and i am not familiar with using oil of ANY type to produce NORI, but it does come seasoned, I have been using Roasted Nori from the MARKET for years! But the ingredients say 100% dried seaweed!