A quiet transformation is weaving itself into the fabric of Hong Kong. In recent years, the city’s social and business circles have been energised by a wave of newcomers from across the Chinese mainland. They have brought with them a culinary revolution – restaurants serving flavours from fiery Sichuan to delicate Zhejiang now dot neighbourhoods once dominated by Cantonese fare. And these tables are magnets for a new cohort of ambitious entrepreneurs, who speak of supply chains stretching into...