He cooked up a storm in Buchanan Street, Glasgow, for an episode of BBC series Landward.
Nairn, along with presenter Sarah Mack, pulled up in their portable cooking-mobile to serve up venison, hake cakes and wild boar sausages to hungry passers-by.
They also cooked and compared wild boar sausages with pork sausages for the crowd.
Nairn said: "Not many would ordinarily cook and buy venison because of the preconceptions about it - that it's too expensive, and that they won't like it.
"And in fact, many of the tasters mistook it for beef, with only one in 10 being able to guess what it was correctly.
"All of them loved the meat, however."
Landward airs on Friday at 7pm on BBC 2.