Stormont is discarding 30 tonnes of food waste a year, it was disclosed.
Almost £300 million was spent on taxpayers subsidising the catering contract in 2016/17, TUV leader Jim Allister said.
He claimed there was a lack of adequate oversight.
"In an age of food banks it is disappointing to be told in an Assembly answer that Stormont is discarding 30 tonnes of food every year."
Mr Allister retrieved the information from the Assembly Commission, which runs the building.
An Assembly spokesperson said: "While the Assembly is not currently sitting, the building and therefore the catering outlets continue to remain fully operational for use by Assembly staff, members and their staff, as well as for visiting groups and organisations.
"The Members' Dining Room is also now open to the public on weekdays for lunch and afternoon tea.
"Food disposal is managed by the Department of Finance's current waste management contractor, who transports it to an organic waste treatment plant, where it is broken down to produce biogas and biofertiliser.
"No food waste is sent to landfill.
"In relation to giving food to charity, the Northern Ireland Assembly cannot do this as the majority of dishes prepared are not suitable for transfer to charity premises under current food safety law."
Mr Allister said it should be remembered that the catering contract generating this waste is already heavily subsidised by the taxpayer.
"The scale of that subsidy is substantial - in 2016/17 it was almost £300 million.
"To then find that 30 tonnes per annum of that subsidised food is going to waste is alarming and speaks to me of a lack of adequate oversight."