Langar
Within the gurdwara, the Guru ka Langar (Guru's community kitchen) serves purely lacto-vegetarian food. This is because the Langar is open to all. Since people of many faiths and having varying dietary taboos, and since Sikhs accept these restrictions and accommodate people no matter their faith or culture, the Sikh Gurus adopt vegetarian food for Langar. Meat was included in langar at the time of Guru Angad, but then discontinued to accommodate Vashnavites. The exception to vegetarian langar today is when Nihangs serve meat on the occasion of Holla Mohalla, and call it Maha Prashad.
Read more about this topic: Diet In Sikhism