250g of butter? Yes, this is probably the least healthy recipe I will ever post. However, homemade Hollandaise is so much better than shop bought. It has a lovely consistency, and a delicious favour, which you can vary according to your own taste.
Ingredients 6 tbsp white wine vinegar
1 slice of onion
4 egg yolks
250g unsalted butter
Squeeze of lemon juice, to taste
NOTE: my quantities make quite a strong tasting Hollandaise sauce, because that's how I like it. You can reduce the white vinegar quantity to make it a little more subtle.
Put the white wine vinegar and onion disk in a pan and bring to the boil. Reduce the white wine vinegar until there is around a third (2 tbsp) left. You can reduce or increase the amount of sauce made by varying the amount of vinegar and eggs up and down. Once reduced, strain the onion out of the vinegar.
Separate the egg yolks from their whites. Set aside the whites (you don't need them in this recipe. Why not make some meringues?).
Pour boling water into a pan, and then turn it down so that it stays at a gentle simmer. The water should not touch the bowl that you'll use for the eggs (otherwise they may curdle).
In a heat-proof bowl, whisk the eggs and vinegar until they are frothy, then put them over the heat.
Cut the butter into small chunks.
Add one piece of butter at a time, whisking continuously. Once the butter is melted, add another piece.
Continue until all the butter is melted in, and the sauce is at "ribbon" stage. This means when you draw your whisk through the sauce, it will leave a trail that will stay on top of the sauce, like a ribbon.
Add freshly-squeezed lemon juice, to taste.
Serve with Eggs Benedict, or with asaparagus spears.
Note: If, at any point, your eggs curdle, its easy to rescue the sauce. Take a fresh egg, separate the yolk, and whisk the raw yolk in to the curdled mixture. This should bring the sauce back and re-emulsify it.