Flan
Two layers, five ingredients: caramel cooked in a saucepan and set in the bottom of the pan, then a milk-and-egg custard baked slowly over it in a tray of water. Overnight in the fridge is not optional — that is when the hard caramel turns back into sauce.
At a glance
Ingredients and method are in the app
Kitchen Pantri holds the full ingredient list and step-by-step method for Flan, 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.