Caipirinha
Brazil's national drink and a three-ingredient one: lime, sugar and cachaça over crushed ice. It is made in the glass in about two minutes, and the only thing that can go wrong is muddling the lime too hard.
At a glance
Ingredients and method are in the app
Kitchen Pantri holds the full ingredient list and step-by-step method for Caipirinha, checks it against what is already in your pantry, and adds anything missing to your shopping list. The app is free to use; you set up a Pantri account when you first open it.