料理

How it works

は (topic) raises the topic (料理りょうり (cooking)) — “as for cooking…”. 得意とくい (good at) is a na-adjective standing on its own as the description. There is no copula and no polite です (is); the bare 得意とくい (good at) plus a rising question mark makes this a casual “are you good at it?”. The subject “you” is never said — context carries it.