To purchase this Sefer, click here
5. How to make Charoses on Yom Tov which falls on Shabbos:
Making it before Shabbos: [The Charoses may be made on Yom Tov in its regular fashion, with exception to] when Yom Tov falls on Shabbos, [in which case] one must make it before Shabbos.
If one forgot to make it before Shabbos: If one forgot to make the Charoses before Shabbos, he may make it on Shabbos [into a thin batter] with an irregularity, which is defined as first place the wine in the vessel and then the Charoses, and to mix it with one’s hand or through shaking the vessel.
 473:34; M”B 321:68; Shabbos Kehalacha 22:80
 Mishneh Berurah 321:64; Peri Megadim 321 M”Z 23; Igros Moshe 4:74 Lash; So also rules Ketzos Hashulchan 130 footnote 9, and explained that this is what Admur meant when saying to look in chapter 321. See above Halacha 2