Musnad Abu Ya'la al-Mawsili 224:1

Ibrahim ibn al-Hajjaj narrated to us, Hammad narrated to us, from Hisham ibn Abi Abd Allah, from Budayl ibn Maysarah, from Abd Allah ibn Utbah, from a woman: That the Messenger of Allah (peace and blessings of Allah be upon him) was brought a bowl of food, and a Bedouin took it with three morsels. The Messenger of Allah (peace and blessings of Allah be upon him) said: "As for it, had he said 'In the name of Allah' (Bismillah), it would have sufficed you all." And he said: "If one of you forgets the name of Allah over his food, let him say when he remembers: 'In the name of Allah, its beginning and its end.'"