- 1 Tbsp chopped shallots
- 1 Tbsp chopped tarragon
- 2.5 Tbsp white wine vinegar
- Salt and pepper
- 2 Egg yolks
- 125g butter, melted and clarified
Add shallot, tarragon, vinegar and a little water to a pan and reduce by 2/3rds. Using a sieve, strain off the herb/vinegar liquid. You will need about 2 tsp for the next step. Note, too much liquid will result in too thin a sauce. Reserve the shallot and herb mix as this can be added back to the sauce at the end, if you wish.
Let the herb/vinegar reduction cool. Place a bowl over a pot of simmering water (Bain Maire). Add the egg yolks and 2 tsp of vinegar reduction. Whisk and cook the egg/herb/vinegar reduction mixture, it will thicken to form a sabayon. Remove the pot mostly from the heat, stopping the cooking. Then very slowly add the clarified butter. It is important to add the melted butter very slowly initially (in drops) until the emulsion takes hold and noticeably thickens. Once it begins to thicken, you add the butter in a dribble as you whisk. Watch the heat is not too strong or the mixture will split.
Add remaining tarragon and stir in. Keep the sauce warm before serving or it will curdle. Add back some of the shallot/herb mixture if you like your sauce that way.
If the sauce won’t thicken and is too thin. Either you have added too much reduction to your eggs or you have added the melted butter too fast. Remove all but 1 tbsp of the sauce from the bowl. Add tsp of the lemon juice or vinegar reduction and whisk in over heat. Once it thickens, start to add the sauce back in slowly as you would the butter.
Sauce curdles? Do the same as if it won’t thicken.
To make a Hollandaise, just skip the reduction, and use lemon juice instead.