It’s a sure sign that molecular gastronomy’s growing up when the city’s top chefs begin to quietly integrate it into their cooking. Guy Rubino, executive chef at Rain, embraces cutting-edge kitchen chemistry as a tool for refining, not redefining, his signature pan-Asian cuisine, especially with his sublime pairing of Wagyu and bluefin tuna three ways. Rubino uses flavourless methylcellulose to morph pure tangerine juice into a lush mousse that’s all sunny citrus flavour. He rekindles diners’ memories of childhood snacks with his sweet, toothsome tangerine fruit leather, bound by a seaweed derivative called sodium alginate. And for the dish’s centrepiece, Rubino “glues” Wagyu beef fat around tuna loin with transglutaminase, a natural enzyme that’s used to bind proteins; when seared, the succulent fat moistens and enriches the lean fish, melding with the tuna flesh to make a powerful combination of umami flavours—no test tubes required. $36. Rain, 19 Mercer St., 416-599-7246.