Recipes & Cooking

This unappetizing green ring — caused by a chemical reaction between iron in the yolk and sulfur in the white — is the result of overcooking. To make sure it doesn’t happen, try this: Place the eggs in a single layer at the bottom of a saucepan, adding just enough water to cover them completely. Bring the water to a full boil, then immediately remove the pan from the heat. Finally, cover with a lid, leaving the eggs to cook in the cooling water for 15 to 20 minutes, but no longer.