פירוש על ביצה 30:1

Our Mishna, On Yom Tov the initial cooking – The initial cooking on principle should be for Shabbat, rather than the initial cooking being for Yom Tov. The remainder can be for Shabbat, as we go on to teach, you can cook for Yom Tov without using a loophole, as taught later on.

Make a dish - for the purpose of the eruv.