"Reb Moshe Feinstein, זצ״ל, ruled that if the chosson and kallah do not wash and partake in the seudah together with the guests, then the Sheva Berachos recited after Birchas HaMazon are considered a berachah levatalah, חס ושלום."
Menashe Frankel has them use EMPIRE poultry, etc. that Reb Shnuer, Z"L did not allow in BMG.
You can (hopefully) ask for kosher fish.
From a comment: This caterer has some serious kashrus concerns that are in the areas of chilul Shabbos, Bishul Akum, Bos'ur Shenis'alem, treif utensils, misleading clientele, etc. R"L
We gave them some better choices from a kashrus point and reliability.
Lakewood caterers, restaurants, take-out, pizza stores, food service, etc. establishments do not all have an acceptable kashrus standard.
Some are more reliable from a kashrus standpoint.
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from a commentor; Others found they could make their families life very easy by going the URI Newman, et al way in kashrus, using Empire, Tartikuv, Minchas Chinuch, Yecvhiel Babad, Weismandel, Star-K, Infested strawberries, infested Sun dried tomatoes, Bossur Shenisalem, Bishul Akum, etc. it does not mean that it's necessarily kosher, but at least one could say, I followed URI Newman's et al protocol. After 120, they'll tell you where to go .