I am in the plane on my way to Heathrow. It is hard for the stranger beside me to avoid being engaged in conversation since my maps stretch over my knees. She joins in the search for Thames Wharf and the quickest way to Hammersmith underground. I explain my mission in London to her and she looks at me with incredulity. I am beginning to feel a little incredulous myself.
Chocolat Nemesis, the sensational chocolate dessert at London's River Cafe, has achieved something approaching notoriety. Since the publication of its book, there have been tales of all sorts of calamities in trying to reproduce it. Some have gone as far as to suggest that there must be mistakes in the recipe and, in wild frustration, have wondered whether they could be deliberate.
It is certainly an unusual recipe in some respects but it is clearly presented. I followed the instructions exactly and achieved partial success: the top half was wonderful, like a giant chocolate truffle, but beneath that was a soggy mess. I tried a long shot and phoned the restaurant and asked to speak to the pastry chef. "Is it about the Nemesis?" came the reply, indicating that I was not the first to try this route.
I got put through to him in the kitchen and was surprised at his level of concern. He told me there were three things to bear in mind. Firstly, I must use good quality chocolate (70 per cent cocoa solids). Secondly, it takes nearer an hour than the 30 minutes suggested in the recipe. Thirdly, it is at its best when left to lie, at a cool room temperature, for at least several hours after being taken out of the oven. He assured me the recipe was correct.
I tried again with the same patchy result and was back on the phone. "Are you ever passing?", he asked with some charm. Sparing him the three kids on summer holidays and the small matter of the Irish Sea, I said that some days are easier than others. Call in on Tuesday around lunchtime, he insisted and he was gone.
Walking through the restaurant five days later I can sense the buzz in the air but, with case in one hand and cake tin in the other, I keep my head down. I change and seek out the pastry section. The ever-patient Gary is doing a hundred other things but he has a small place cleared and has everything weighed out. I know the recipe by heart. There are just four ingredients: 675 grams of very finely chopped chocolate, 10 whole eggs, 575 grams of sugar and 450 grams of unsalted butter. No signs of any secret additions.
I take one of their tins (30 x 5 cm), line it with a circle of bakewell paper and grease it well. I beat the 10 eggs with a third of the sugar in an electric mixer for about 10 minutes until the volume quadruples. I heat the remaining sugar in a small pan with 250 ml water until the sugar has completely dissolved to a syrup. I check the weight of the chocolate and put it with the softened unsalted butter into the hot syrup and stir. My concentration is broken for a second by someone looking over my shoulder. I must be losing it; he is the image of Dustin Hoffman.
I ignore him and get back to the task, pour the warm chocolate mixture onto the eggs and beat just long enough for them to blend together. I pour the mixture into the cake tin where it fits snugly. I inquire about the tins. He says that they come from New York (I think I have travelled far enough). Gary points to an oven (pre-heated to 140 C.) where there is a bain-marie of hot water. I put the tin in the bain-marie, to which I add little more water so that it comes right up to the rim of the tin. Now I relax and look around (that really is Dustin Hoffman wandering around). I head off around the pots, looking, listening and questioning. The chefs are unfazed by my interruptions. After 45 minutes I peep into the oven, gently press the top and reckon it needs a little longer. Ten minutes later, I take it out and Gary inspects, nods and pushes it to one side. It is left to cool in its water bath. I am swept along in other things.
Several hours later, when the dessert has completely cooled, he places a large plate over the tin and flips it upside down. The top is quite soft, almost mousse-like. It will set perfectly, and become easier to slice, with a little more time. There is a lull in the kitchen and a few gather around. It really bothers them that people have had trouble with this dessert. They are intrigued because their usual advice has not helped me. They all taste my effort and are satisfied that this Nemesis is up to scratch. They are curious as to what I do differently at home. So am I. They ask me about all the usual suspects: the chocolate, the oven, letting it cool in the tin. They are baffled. It seems a wasted journey. They disperse.
A little disconsolate, I go back to the changing area where I see my trusty tin. Gary has already queried whether I have been using a spring-form pan that would leak in the bain-marie but I know my faithful old Christmas cake size tin is completely seaworthy. As I pick it up, I am struck by its depth. And then it hits me. I rush in to Gary and we agree that condensation on the sides of the deeper tin may well be the source of my problem. We make another batch of Nememis and this time pour it into my tin. It emerges an hour later looking fine. The moment of truth comes when it has cooled and Gary turns it out. I feel a wave of satisfaction as he has to scrape the watery mess into the bin. For one cook the puzzle of the Nemesis has been solved.
Lynda Booth meets her nemesis