This was the sauce we had with the first course at dinner on Christmas Day. A classic technique, but none the worse for that! As with all good sauces, the secret is to reduce, and reduce, and reduce - so all those wonderful flavours end up concentrated in a spoonful of something which is so luxuriously delicious that it practically defies description.
On this occasion, we were eight for dinner, and I had a couple of gloriously meaty Dover Sole, the fillets from which were 'poached' over chopped shallots and white wine in a gentle oven, and then served with a light coating of sauce. In practice, the sauce will work with any white-fleshed fish....and if you don't want to faff around with the filleting and making the stock from scratch, then substitute a quarter cup of ready made (good) fish stock, add to it the same quantity of white wine, and then reduce by a half before proceeding with step two of the recipe.
You can make the sauce in advance, but if you do, then be very careful when reheating, and only do it slowly, and over the gentlest of flames.
Makes sufficient sauce for 6-8 servings (2 tbs each)
Ingredients: 2 fish carcasses;1 bottle dry white wine;1 pint of creme fraiche* - preferably home made**;1 stick celery;parsley stalks and/or fennel stalk;1 onion, roughly chopped.
1. Poach the vegetables and the fish carcases in the wine for an hour. Strain, discard the carcases and vegetables, and reduce the stock to next to nothing - ¼ cup say.
2. Add the cream and reduce until you have 250ml or 2 tablespoons per serving. Season before serving.
* Creme fraiche is acid and produces a completely difference sauce to, say, double cream. You can use double cream and add lemon juice, but the flavour will not be the same. I also find double cream has a greater tendency to 'split' than creme fraiche.
**To make creme fraiche at home, you will need to buy a small amount of creme fraiche the first time in order to start the process (and then use the tail-end of the first batch when it comes to making the next lot).
Heat a litre of whipping cream to 40°C - I buy screw top paper cartons and put the carton in the warming drawer. As when making yoghurt, mix a couple of tablespoons of existing creme fraiche with some of the cream from the carton. Mix very well and return the liquid to the carton. Turn the carton upside down a couple of times to amalgamate and leave in a warm place(22-24°C say) for 24 hours. Turn the carton upside down occasionally to mix the contents. I sit the container on top of the gas central heating boiler. Refrigerate for a day before using. It will keep 10 days or more.