On the elements? No, it's not really like that... [Katara will take the tea and follow Sanji to the table.]

Aang can use all the elements, or at least he could by the end of the war, according to Sokka. But the Avatar's job is about keeping balance, whether it's between nations or the spirit world and our world, or just between people.

[A pause as she looks at the plate Sanji prepared.] Wow, Sanji. This looks amazing.