Eggs are a great source of protein, iron and vitamins, and they're easy to cook Delia Smith, a famous British cookery writer and TV chef, was criticised by professional chefs when she wrote a book containing a recipe for boiled eggs. But many ordinary people were grateful to receive such instructions. Since the demise of cookery lessons in the UK, the majority of school graduates lack the basic skills to cook for themselves at university. So how do you cook the perfect boiled egg? According to Delia Smith you should take the egg out of the fridge and let it come to room temperature. Next, place the egg in a small saucepan and add enough cold water to cover the egg by one centimetre. Put the saucepan onto a high heat and, once the water has boiled, reduce the heat to low and let it simmer for three to five minutes, depending on how soft you want your yolk. If you want a hard-boiled egg, then simmer it for seven minutes. Eggs are a great source of digestible protein, iron, B vitamins riboflavin and folate, and vitamins B12, E and D. One large egg contains about 7g protein, 5g fat and 70 calories. Eggs and cholesterol Cholesterol is needed to make the cell membranes that protect our nerves. It's also needed to make hormones such as oestrogen, and acids which help to digest fats. The body can usually make all the cholesterol it needs. According to the American Heart Association, cholesterol from food isn't required and is actually unwelcome: too much cholesterol can clog your arteries and lead to a heart attack. The recommendation from the US National Heart, Lunch and Blood Institute is to limit your intake to no more than four egg yolks a week - that includes egg yolks in baked products. Egg whites are cholesterol-free, so the Institute recommends replacing one single whole egg with two egg whites for breakfast foods and baked goods. UK dietitians recommend no more than three eggs per week.