In front of a crowd of delighted University of Derby students, The Prince added dressing to a warm salad of smoked venison, root vegetables and salad leaves.
Catering is just one of the courses on offer at the campus, which is also the base for the University of Derby’s courses in tourism, hospitality and beauty therapies.
Traditional building skills and methods were used in the refurbishment of the hospital, for example, the matching of original lime and goat’s hair plaster, using Buxton quicklime and goat’s hair from Devon.
The Prince, who is a keen advocate of the preservation of traditional building skills, has spoken for many years of their importance in ensuring the preservation of heritage buildings like the Devonshire.
In the basement of the building, one of England's few warm spas is in the process of being restored.
Above - The Duchess officially starts a model of Foucault's Pendulum during a visit to the University of Derby.
The Prince and The Duchess were shown the ongoing work in the 90-year-old spa, which will be used by students practising water therapies.
During the tour of the campus they also visited the vocational training rooms where students learn beauty treatments, massage techniques and hairdressing skills.
The Duchess also officially started a model of Foucault's Pendulum in the centre of the dome, which demonstrates the rotation of the earth.
Unveiling a plaque to mark the opening of the campus, The Prince told a crowd of students, staff and dignitaries: "I must say that I was so anxious that a new use could be found for this very special place.
"I can't tell you how proud it makes me and my wife to be here on this special occasion of bringing this building back to life.”
“As someone who is extremely interested in heritage-led projects this is a wonderful example of what can be achieved.
“Projects which aim to bring buildings back to life present a big challenge – but by God, it’s worthwhile in the end.”