A greenish ring around the yolk of a hard-cooked egg is a common, harmless occurrence  caused by the formation of iron sulfide. To lessen the possibility of such rings forming, carefully watch the cooking time and immediately cool eggs.

Place 6 eggs in shells in a large saucepan; add enough water to cover eggs. Bring to a rapid boil over high heat. Reduce heat so water is just below simmering; cover. For soft-cooked eggs, cook 4 to 6 minutes. For hard cooked eggs, cook 15 to 20 minutes. Pour off water. Serves 3.

For soft cooked eggs , add cold water just till eggs are cool enough to handle. Cut off tops and serve in egg cups. (Or, remove egg from shell by cutting egg in half and scooping out the egg into a dish.)

For hard cooked eggs, fill a saucepan with cold water and let stand at least 2 minutes. To quickly cool, add a few ice cubes.

To remove shell of hard-cooked eggs, gently tap warm egg on a counter top; roll egg between palms. Peel off the eggshell, starting at large end.

Rosy pickled egg recipe that calls for hard-cooked egg

Healthy Low Carb Diabetic Diet