During the time of the Mishna, some communities had a custom to refrain from eating roast meat on Pesaḥ night, since it would look like they were eating the meat of the Paschal sacrifice – which must be roasted – outside the precincts of Jerusalem. Elsewhere, people did eat roast meat on Pesaḥ but did not roast a whole lamb, which would really look like offering the korban Pesaḥ outside the Temple. The Sages stated that each custom is valid: where the custom is to refrain from roasted meat, one should not eat it, and where the custom is to eat it, one may (Pesaḥim 53a). In practice, Yemeni Jews customarily eat roasted meat on Pesaḥ night, but all Ashkenazim and most Sephardim customarily prohibit roasted meat on Pesaḥ night (Ben Ish Ḥai, Year One, Tzav 30; Ḥazon Ovadia p. 175). We shall now specify the details of this prohibition:
The prohibition against roasted meat applies to all types of meat, even from species that could not be used as the korban Pesaḥ, such as beef and fowl. However, one may roast foods that do not require ritual slaughtering, such as fish and eggs (SA 476:2). Though the meat of the Paschal sacrifice was roasted over the fire and not in a pot, pot roast is nevertheless forbidden, because it looks like meat roasted over fire. It is likewise forbidden to eat meat that was first cooked and then roasted, because it looks roasted. However, meat that was first roasted may be cooked and eaten on the Seder night, because it looks cooked (MB 476:1; Kaf Ha-ḥayim 4 ad loc.).
Some have a custom to eat eggs during the Seder meal in order to recall the destruction of the Temple, as eggs are a sign of mourning, and because the first day of Pesaḥ always falls on the same day of the week as Tisha Be-Av (Rema 476:2). The Vilna Gaon explains that eggs commemorate the pilgrimage sacrifice (korban ḥagiga) that was eaten on the Seder night before the korban Pesaḥ. Therefore, the custom is to eat the egg from the Seder plate during the meal, as it is placed there to commemorate the korban ḥagiga (MB 476:11; Kaf Ha-ḥayim 25-26 ad loc.). Some people refrain from eating the egg from the Seder plate in order to keep the plate intact; they eat it on the following day (Ma’amar Mordechai 473:1). However, the widespread custom is to eat the egg from the Seder plate at the Seder.
As on any other Yom Tov, a distinguished feast should be prepared for the Seder night, with fine silverware and festive delicacies. One may drink wine during the meal; this is not considered adding to the four cups. However, one must be careful not to eat and drink too much, so that he has the strength to eat the afikoman with an appetite at the end of the meal (see the next section) and because one must be able to continue reciting the Hallel and the concluding songs and continue recounting the story of the Exodus.