In the understated Persian restaurant Moby Dick of Boston, near Symphony, owner Moti Bakhtiari is brewing up something with more power than any can of Red Bull. Her homemade Moti’s energy drink ($3.95) is bright orange and fragrant with steamed rose, Iranian saffron, lemon and lime juice, and a secret Iranian mountain herb. Bakhtiari began bottling her elixir and selling it by the case ($48) last summer, after nearly a decade serving it to devoted fans. Regulars buy it in bulk. Bakhtiari herself drinks half a bottle every morning. It’s the reason she gives for being able, at 60, to work long days cooking and engaging customers with her trademark vigor. “I never get sick and I’m always happy and I work hard,” she says, grinning. Medicine never tasted so good. Moby Dick of Boston, 269 Huntington Ave., Boston, 617-236-5511.