Hollandaise is something that takes practice, and even then it can go wrong. The first one can turn out brilliant, and you can get complacent and think you are the bees knees of sauce makers, and then the next time it doesn't thicken or it curdles. Don't get disheartened. It happens to the best sous chefs. Make sure that as a home cook, your dish does not rely solely on your sauce and you can recover!

Ingredients
4 ozs of butter
2 egg yolks
1 tablespoon of lemon juice
Splash of cayenne pepper or hot paprika
Salt (about 1/4 teaspoon)

1. Put a few inches of water into a saucepan and bring it to the boil, then turn it down to a simmer. Put a heatproof bowl on top that fits so that the bowl is not touching the water.
2. Put half the butter into the bowl on top. Add the egg yolks and lemon juice. Stir until the butter is melted. Add the rest of the butter and keep stirring, making sure that the water underneath is not boiling as it will curdle the eggs.
3. Keep stirring, until it thickens. It can take a while.
4. When it has thickened, add the cayenne or hot paprika.

Cooks Note
If it curdles, you can take the bowl off the heat and put the bottom in cold water, then whisk it. Or you can take it off the heat and add some cream, drop by drop.

Bearnaise sauce
This is an easy way to make a Bearnaise sauce – it's essentially a hollandaise sauce with a few more ingredients added.

Ingredients
3/4 cup of vinegar
A pinch of salt
A pinch of white pepper
2 shallots, chopped finely

Method
Heat the vinegar, salt, pepper and shallots together until they have reduced to about a tablespoon. You want a dense flavour. Add it drop by drop to Hollandaise sauce.