"A cocktail made from Mexican beer, gin and lemon juice. The ingredients complement each other: the beer smooths the gin, and the gin/lemon de-fizzes the beer. Make sure everything is cold before preparing. More is not better: Using more than a half shot of gin or lemon will ruin the flavor. Gins vary widely in flavor. While other gins can be used, the original gin used by the creator is Tanqueray. Don't use lime as a substitute for lemon."
Drink or pour out the beer to the level at which the neck widens, making room for the other ingredients. Pour in the gin and lemon juice. Secure the opening of the bottle using your thumb and gently rock the bottle to mix the ingredients. Drink and enjoy.