Della Callagher, 46, felt ill after the meal at the Railway Hotel and was taken to the Queen's Hospital in Romford, her husband John told the Evening Standard.
The hospital effectively turned my wife away when there could have been more of a chance of saving her life.
It was disgusting the way she was dealt with.
We were about to celebrate our 25th wedding anniversary.
Della was so fit and healthy, I can’t believe it. This is devastating.
Dr Mike Gill, Medical Director at Queen's Hospital, said:
A patient attended our Emergency Department on Boxing Day with what appeared to be food poisoning. The patient was seen and fully assessed by a senior clinician, and given appropriate treatment and advice before returning home.
The Trust followed accepted medical practice. We will be fully reviewing the case. We have written to the family offering our condolences at this very difficult time and inviting them to meet with medical staff who can answer any queries or concerns they may have.