Put a plate in the bottom of a large saucepan. Fill the pan with water, clip on a cooking thermometer and bring the temperature to 63°C (113°F) over a medium heat.
Gently lower in the eggs. Keep an eye on the temperature of the water, as you want the eggs to cook for 1 hour at a constant of about 63°C (113°F). A degree or two above or below won’t kill you, but try to find the temperature sweet spot on your stove. It might help if your saucepan sits part-way off the heat. Have some ice on hand in case the temperature spikes and add ice cubes one by one until the temperature lowers. After an hour, carefully remove the eggs from their bath, and they’re done.