This is an excellent recipe, and it works. It's based on a Raymond Blanc dish from his book Cooking for Friends. I first made it for The Girl when we were steppin' out; now she's Mrs Aitch, so I obviously did something right. It's for four people.
First, you need to pre-heat your oven to 330F (160C), Gas mark 3.
Take 150 g of fresh scallops and remove the orangey coral bit. Put these to one side. Purée the scallops in a food processor for two minutes (that's quite a long time, but it's needed to make sure the mixture turns very, very smooth), and then add a single egg yolk, salt and cayenne pepper. Mix, until all the ingredients are incorporated.
Next, take the bowl of your Magimix (with the purée inside) and stick it in the deep freeze for 15 minutes: this will help to stop the mixture separating when you add cream. When the time's up, take out the bowl and put it back onto the Magimix. Set the motor to medium speed, and slowly pour in 200ml of whipping cream- in a thin stream. Taste and season again, if you think it needs it.
The mousse is going to be cooked in oven-proof porcelain ramekin dishes, and then turned out. I used a set of 80's Villeroy & Boch ramekins that I happened to have lying around in the cupboard. They were too deep, in my 'umble opinion, as the result was too much mousse on the plate. Maybe tastes have changed? For a decent First Course, I think less is probably more, and I would recommend either using those shallow ramekins or reasonably small moulds instead: you're not cooking the main event.
Smear the insides of your ramekins with butter, and then fill 'em up with the mousse mixture. Place the ramekins inside a roasting tin, and pour in boiling water, so that it comes up to two-thirds of the ramekin dishes. Cover the tray loosely with some tin-foil and stick it in the pre-heated oven. It's going to take 15 minutes to cook.
In the meantime, you need to make your sauce. Melt 15g unsalted butter in a small pan and sweat a chopped up shallot or two, a few finely chopped button mushrooms and the coral from the scallops. After a few minutes, add a slug of Noilly Prat or Martini Extra Dry Vermouth. Turn up the heat and boil quickly, to reduce by half. Add a few tablespoons of water and two tablespoons of whipping cream. Push the mixture through a fine sieve, pressing down hard to extract as much as the fishy mushroomy juice as possible, into a clean pan.
Next, on a very low heat, gradually whisk 1/2 oz of diced butter into the sauce, so that it forms an emulsion. Taste, season with salt and white pepper, and whisk in a few drops of lemon juice.
Take the ramekins out of the oven. You'll find that the mousses will turn out very easily, as long as you run a knife around the edges of the ramekins. Place the mousse on the centre of the plate, and spoon over the butter sauce. You can either add chopped chives to the sauce at the end of the cooking stage, or when the sauce is on the plate.
A quick note about the chives: don't make the mistake I made of adding far too many chopped chives- it will turn your sauce a muddy green colour. You want your sauce to be a butter yellow. I would recommend that you add the finely chopped chives in small amounts, or even add the chives in tiny piles to the hot butter sauce when it's already on the plate. My other mistake was to swamp the delicate mousse with the rich butter sauce, so that it came up to the very edge of the plate. I would suggest that you go easy on the sauce, and just spoon it over the mousse in a modest way.
Once you've mastered the technique of mousse-making (and the Blanc method as described above is a good one), you can start thinking of other ingredients. I'm considering the idea of a Smoked Haddock Mousse with an Anchovy and Butter sauce. Obviously, you would need to add anchovy essence in very small quantities, otherwise the whole thing would be far too salty. There might be a cleverer way of adding the flavour of the anchovy? Maybe Smoked Haddock Mousse with a Butter and Parsley Sauce might be a better idea? Time to get my thinking cap on. Any suggestions?
