Q. If someone has the minhag (tradition) to eat a milk meal on the first night of Shavuot, and then after cleaning ones’ hands and mouth, go to another nearby table and eat some meat and drink wine, to comply with the traditions of this Yom Tov, can one then use the same Chalot (breads), or should one recite Birchat Hamazon and wash again so not to incur in a mixed meal of meat and milk?
A. Poskim disagree if bread has to be eaten on the second meat meal that night. Madanei Yom Tov (Brachot 7:23:7) writes that meat is to be eaten with bread for Simchat Yom Tov. However, some sources hold that meat can be eaten outside of a bread meal. Nevertheless, indeed the same breads should not be used for both meals.
Poskim maintain that according to the Rashba, seemingly there is no obligation to eat the meat in a bread meal since the obligation for the meat and the bread stem from two different places. The obligation of bread is motivated by Oneg Yom Tov. However, the meat is because of simcha (Pesachim 109a). Furthermore, the obligation to have a bread meal at all on Yom Tov is a debate. The Rambam, is the one who holds that it is necessary to have meat meal, holds that there's no obligation to have a bread meal on Yom Tov besides on the first night of Pesach and Sukkot. However, the description of the Rama of how to have dairy and meat in the meal of Shavuot in order to fulfill simchat Yom Tov is within the context of a bread meal.
Rabbi A. Bartfeld as revised by Horav Y. Hirshman, Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu, Horav Kalman Ochs, and Horav Dovid Bartfeld consulting in need Horav Hagaon Rav Yitzchak Berkowitz Shlit’a