It’s a far cry from, say, London, where time is money, and so are ingredients and firewood and outside space. Yet the capital has witnessed a wave of Texas barbecue-inspired restaurant openings in recent years, led by the success of YouTube channels such as HowToBBQRight, BBQwithFranklin and Mad Scientist BBQ, and TV shows such as Chef’s Table BBQ and BBQ Pitmasters, appealing to the growing number of Americans applying for British citizenship.