1. Place a single layer of large eggs in a saucepan.
2. Cover eggs with at least one inch of tap water.
3. Cover the pan and quickly bring to just boiling.
4. Turn off the heat. Remove pan from burner to prevent further boiling, and let the eggs stay covered in the hot water for about 15 minutes. (12 minutes for medium eggs; 18 minutes for Extra-Large)
5. When time is up, run cold water over eggs or place them in ice water until completely cooled.
6. Store hard-cooked eggs in their shells in the refrigerator, and eat them within one week.
7. Easy peel: Crack shell by tapping gently all over. Roll egg between hands to loosen shell, then remove shell under running water.
The greenish-gray ring that sometimes forms around the yolk of hard-cooked eggs is caused by a chemical reaction between naturally occurring iron and sulfur. The ring, which is harmless (though not pretty), forms when eggs are cooked too long or held at too-high temperatures. Chilling the eggs in cold water after cooking helps prevent the ring.