We all think we know best, but now tests carried out by Cook’s Illustrated magazine reveal the most reliable way to prepare perfect eggs.

The latest issue of the American publication devotes two pages to the fine art of frying the humble egg.

The key findings showed that putting a lid on the pan will help the whites set before the yolk overcooks.

According to the magazine, you can be sure to make excellent eggs by following a few simple rules.

Start by preheating the pan thoroughly, for about 5 minutes, to ensure even cooking. Preheat over low, then increase to medium-high before adding the eggs.

Use a combination of oil, whose higher smoke point allows ample preheating without burning, followed by butter, which adds great “diner-style richness” and flavor.

Add all of the eggs at the same time. To do this, first crack them all into a bowl.  Finish cooking the eggs away from the heat. A gentle finish will help keep the yolks liquid.

The magazine suggests to cook the eggs on medium-high and covered for 1 minute, then off the heat and still covered for 15 to 60 seconds, depending on how liquid or firm a yolk is desired.