Most fancy drinks are sweet—often to a fault. That means they’re also high in calories thanks to all those added juices and mixers.
A smarter—and leaner—option? Replace sugar with the char and ash of smoke. Here, we use stovetop-charred lemons. Give it a shot.
Preheat a cast iron or stainless steel skillet over high heat. Add lemon halves cut-side down, and cook until well-charred, about 2 minutes. Let cool.
In a rocks glass, muddle charred lemons, rosemary, and simple syrup. Add gin and ice. Top with tonic, and serve.