The key is to get small potatoes no bigger than a golf ball, and boil them until they’re just fully cooked and the potatoes slide off your knife when you test. For maximum crispiness, let them sit in your colander for five minutes so any excess water evaporates, and then crush them with a heavy pot until they’re just under a centimeter thick. Brush them with oil, roast them in the oven, and finish them with some coriander lime butter! So good and easy!