Reaction Coffee Roasters is a cafe in Tsim Sha Tsui on Mody Road, near the K11 Art Mall. It serves dirty tiramisu, brunch, and specialty coffee, with a black truffle scrambled egg burger and dirty tiramisu as its signature items. Beans are sold one week after roasting, and customers can choose from acidic, nutty, fruity, or decaf options. Orders are placed by QR code and paid at the counter on the way out, and food sometimes arrives more than 30 minutes late.