"요리법을 따르면 양파하고 배추가 필요해요."
Translation:According to the recipe, you need onions and Napa cabbage.
I've never heard it called "napa" cabbage. Even my dictionary says "Chinese cabbage."
Actually that's a folk etymology/assumption: "regional and colloquial Japanese term 菜っ葉 (nappa, “leaves of any vegetable”)."
You is not always said in Korean. Just like I is sometimes dropped at the beginning of a sentence