Egg

Two proteins on two separate setting curves, which is what makes precise timing possible. Ovalbumin and ovotransferrin in the white begin setting around 62 degrees Celsius and are firm by 80. The yolk's low-density lipoproteins and livetins do not fully set until nearer 70 throughout. A jammy egg is the window where the white is fully set and the yolk core is still around 65: fridge-cold into hard-boiling water, 6 minutes 30 seconds, straight into iced water. The bath is not optional. It stops the carryover, which is worth roughly two more minutes of cooking, and it contracts the white off the inner membrane so the shell releases cleanly.