Al-Wahshiyyi ibn Harb radiallaahu ‘anhu related that some of the Companions of Allaah’s Messenger sallallaahu ‘alayhi wa sallam said:
O Messenger of Allaah! We eat, but do not become satisfied.
So he said to them: “Perhaps you eat separately?”
So they replied: Yes.
So he said: “Eat your food collectively, mention the Name of Allaah upon it, then there will be blessings for you in it.”
Shaykh Ibn al-‘Uthaymeen said:
“This indicates that it is essential to eat collectively from a single plate. So if there are five or ten people, they should eat collectively from a single dish, depending upon the situation. Indeed, doing so is a cause for barakah (blessings) to descend, whilst eating separately is a cause for barakah to depart.”
 Hasan: Related by Abu Daawood (no.3764). It was authenticated by al-Haafidh al-‘lraaqee in his Takhreejul-lhyaa (214).
 Sharh Riyaadhus-Saaliheen (7/231) of Ibn al-‘Uthaymeen.
Source for the above: Al-Istiqaamah Newsletter, Shawwaal 1418H / February 1998 ,Issue No.8
The following is taken from Imam Al-Nawawi’s Riyad-us-Saliheen – Chapter 107 :
745. `Abdullah bin Busr (May Allah be pleased with him) reported: The Prophet (sallallaahu ’alayhi wa sallam) had a large bowl called Al-Gharra’, which would be carried by four men. One day, when the Companions finished their Duha (forenoon optional) prayer, Al-Gharra’ was brought full of sopped bread, meat and broth, and they sat down around it. When their number increased, Messenger of Allah (sallallaahu ’alayhi wa sallam) sat down on his knees and rested on the soles of his feet. A bedouin said to him: “What sort of sitting is that?” Thereupon Messenger of Allah (sallallaahu ’alayhi wa sallam) said, “Verily, Allah has made me a courteous slave not a fierce tyrant.” Then he said, “Eat from the sides of the bowl and leave the central part of it so that your food will be blessed.” [Abu Dawud].