Charles and Camilla are underpinning a Big Lunch project benefiting six million people a year, one of its organisers has said.
They joined community volunteers and schoolchildren in Lisnaskea in Co Fermanagh who enjoyed a spread of scones and cream and copious cups of tea on long communal tables.
The Big Lunch is a National Lottery-funded project intended to bring people together.
Peter Stewart, a director at the Eden Project educational charity and social enterprise, said it was like the US Thanksgiving holiday, but for neighbours.
"Your Royal Highness, forgive me, because it is her Royal Highness who in fact in our eyes is the star of the show," he said.
"You are a passionate man in underpinning this.
"You are almost like a good wind under our wings."
Camilla chatted with staff from Fermanagh's Oak Healthy Living Centre during their visit to the Archdale Centre in the lakeland county yesterday afternoon.
She loved the "caterpillars", kebab-style sticks skewering green grapes with a strawberry on top, those who met her said.
The bananas had red bandana-style decorations on them and were devoured by the youngsters.
Mr Stewart said the National Lottery had funded six million people a year to enjoy a Big Lunch.
"It just seems everything we do, it just seems to be more and more challenges for all of us," he said. "It feels sometimes that we are like a fish going the wrong way up the stream - it is really hard.
"The challenges that we have are global, national, local, massive.
"We think that if we actually got together a bit in terms of creating happier, more resilient, stronger communities, at least we will be better placed to be able to take that on."
The healthy living centre works with people from birth to old age and provides mental health and physical activity programmes as well as encouraging healthy eating.
In an open air area known as the Cornmarket the smell of bacon filled the air.
Patrick O'Doherty (58) explained the "ancient" bacon they made in Fermanagh, which he said was the oldest type in Ireland.
The method died out during the 1960s and he resurrected it and named it Fermanagh Black Bacon, based in nearby Enniskillen, from pigs grazing on an island in Lough Erne.
The bacon was originally cooked in hay, immersed in boiling water with herbs and then poached gently.
Mr O'Doherty said: "The prince, he is a good man with a knife, he cut open the hay and you had to slice it and it is the most beautiful bacon you will ever eat, it is lovely and moist.
"He really enjoyed it."
Charles was also shown an old trick from the butchery trade which involved knotting a string and pulling it.
Mr O'Doherty said: "He was very impressed with it. It is not often you get a fist pump from a prince so it was a good day's craic. He has a great sense of humour."
The royal couple met a number of well-wishers gathered on the street outside and visited a local shop, while Camilla petted a terrier.