It is a commandment to place an eruv tavshilin on the eve of the festival • This permits cooking and baking for the Sabbath on the festival • Even one who does not intend to cook for the Sabbath on the festival is commanded to place an eruv tavshilin.
"Halacha in 60 Seconds": The eminent Posk Rabbi Binyamin Hota presents a short and topical daily Halacha section every morning on Kikar Hashabbat, which summarizes the details of the laws and customs.
And in the daily section: Halacha on cooking during Shavuot, which this year is close to Shabbat Kodesh, and we are mixing dishes - when is it permissible to cook?
Watch the Halacha - in the video at the beginning of the article