Combine all ingredients with ice in a cocktail shaker or large glass. Stir the mixture thoroughly and strain into a coupe. Garnish with an orange twist.
Try it with a autumnal gin to gear it more toward the fall season. The original recipe calls for any red vermouth, I've only ever used Dolin Rouge.
There's a similar gin drink made with 1/2 oz of dry vermouth, 1/2 oz sweet vermouth, grenadine and orange juice so this may be a variation on that.