For hard boiled eggs, place room temperature eggs in a deep pot filled with cold water, being sure to submerge eggs completely. Don't overcrowd each egg needs to be surrounded by water.
For hard boiled eggs, once the water has started to boil, remove the pot from heat, cover, and set aside for 15 minutes. Then plunge the eggs into an icewater bath to stop the cooking; this will significantly reduce the possibility of the yolk developing that unpleasant green tinge.
For soft-boiled eggs, bring a large pot of water to a slow boil; carefully lover the eggs into the gently boiling water. Lower heat to a bare simmer and cook for three to four minutes. Run cold water over the eggs briefly, crack the eggs and transer to a bowl; eat at once. (for medium-boiled eggs, increase the cooking time to 7 minutes.)