From chai-flavored cheesecake to tea-smoked tofu, with a scoop or two of green tea ice cream in between, cooking with tea is taking culinary circles by stealth. As current-day cooks expand on these traditional tea uses, they are discovering that even simple, subtle additions—a jasmine tea bag or two simmered with rice, or a tablespoon of brewed English Breakfast whisked into a salad dressing—can add a richness and depth to foods without overpowering their natural flavors.