Paul Campbell, the chief executive of Clapham House, which owns the Gourmet Burger Kitchen chain, has taken a personal stake in Tortilla, the Mexican food company. Campbell, who has become a director of the firm, is taking what he described as a "meaningful holding" in the London company, with an option to take a bigger stake in the future should the firm continue to prosper. "Tortilla really reminds me of GBK," said Campbell, a former finance director of the Pizza Express chain. "Mexican food is growing in popularity in Britain and Tortilla is a great business." Tortilla is run by Brandon Stephens, a Princeton graduate who used to run retailer Arcadia's e-commerce business in London. So far, Tortilla has four restaurants in London with plans to launch another four in the capital and the surrounding area this year. The Independent on Sunday, p81