Put the shallots, tarragon, crushed pepper and vinegar into one of the small saucepans. Bring the mixture to the boil and let it reduce to a moist purée. Allow it to cool.
In the other saucepan, cook the tomato pulp until the liquid has completely evaporated.
To the first saucepan, add the tablespoon of cold water and the two egg yolks. Put it back ov