Turn Your Diablo Cocktail Into a Lemony Tequila Punch

Fruity but not sweet. Tangy but not sour. Fizzy but not weak. Boozy but not heavy. It's a lot to ask of a drink, but this refreshing punch makes all the right moves.

The recipe began, as many do, with a classic cocktail. "The Diablo was one of the first little-known classic cocktails I learned how to make back in the '90s," Clyde Common bar director Jeffrey Morgenthaler wrote me recently. "I've always been a little obsessed with it," he adds. The Diablo is already a tall, fizzy drink, made rich and earthy with crème de cassis, and spiked with herbal tequila. But Morgenthaler goes further, tweaking the recipe into a summer punch to add to Clyde's daily overflowing bowl. "Those flavors are just meant to be sipped on a hot day," he says.

So I started with Morgenthaler's recipe, which goes a time-honored punch route, calling for a bittersweet and fragrant oleo-saccharum syrup made from sugar and lemon peels. The syrup is added to a mix of black tea, tequila, cassis, and lime juice, then frothed out with club soda or seltzer.

And that makes sense in a bar: You make huge batches of oleo-saccharum (Morgenthaler uses a vacuum-sealing method) out of lemons, and you can use the lemon juice in another drink that you're selling. But at home it feels crazy to buy and process a pile of lemons and still need to juice up limes for the actual drink.

Luckily, this punch is even better when we simplify. Forget the double citrus plan. Instead, you'll juice some lemons and use them to make a super-intense variation of Stella's killer sliced-lemon syrup. It's extra-packed with tangy flavor, and much more aromatic than the traditional peels-only sort.

Once the sugar's all dissolved and it has pulled flavor from the lemon chunks, you're ready to add the tea, reserved lemon juice, tequila, and cassis. The liqueur adds a deep, ripe flavor that'll remind you of going berry picking: the vines baking in the summer sun, the sweet juice smeared on your hands. But the cleanup's a lot easier.

As we all know, when it comes to entertaining, the devil's in the last-minute details. Make it easy on yourself and get this punch prepped in the morning—you can refrigerate the lemon-tequila-cassis mixture up to ten hours in advance without the lemon's flavor suffering. When your party's started, you'll just add seltzer and pour each serving into an ice-filled glass.