The Noon Day Rest was painted by the St Agnes artist Edward Opie some time in the middle of the 19th century.

It depicts a family lunch somewhere on the north coast of Cornwall at a time when the pasty was the staple diet of miners who worked in the copper and tin industry.

The pasty was the staple diet of Cornish miners

The trademark handle of crust was designed so that miners whose hands were often contaminated with poisonous metals and arsenic could discard that part after their meal.

Viv Hendra, from the Lander Gallery in Truro said the earliest photographic evidence of the region's most famous foodstuff dated back to the early 1900s.

But the painting's unique selling point is that it pre-dates any photograph.

Mr Hendra added that at least one Cornish pasty-making firm had shown an interest in buying the painting.