For this sauce you can either slice whole smoked salmon, or if you can get it, use off-cuts from a fish-monger which is considerably cheaper. Chop the slices of smoked salmon as small as you can. It is possible to do it in a blender, but there is a risk that the smoked salmon will heat and become a lump of plastic from which there is no return. Consequently I use a knife.

Melt two ounces of butter in a pan and add the chopped smoked salmon. Turn the heat down low and let it cook. It will lighten in colour as it cooks. Use the back of a fork and mash the salmon into a paste as it cooks. It will begin to thicken at this point, so now is the time to add cream. Add enough cream to bring the sauce to the desired consistency. It will be pale in colour at this stage stage, so add a teaspoonful of tomato puree to bring back the colour. The sauce is now ready and can be kept on a low heat until it's needed. If it thickens up, add a splash more cream. Just before serving add a splash of cognac or brandy and stir it in.