This portrait of early 20th-century Russian Jewish immigrants to the West, by French symbolist Lucien Lévy-Dhurmer, goes on sale on Tuesday at Christies in London.

But its owner, art expert and Satmar Chasid, Marton Braun, plans to put the hoped-for £30,000 proceeds to unusual use; funding the start-up of his new venture, a non-dairy frozen dessert.

It cannot be called ice cream, explained one of his partners David Russell, “because it does not have milk or cream in it. So we are labelling it Ice Dream instead.”

Having just acquired its kosher licence, it goes on sale under the brand name Antonio Russo in four flavours.