Boil the peeled asparagus in 1L of water. When they are tender, set the asparagus aside and reserve cooking water. Prepare béchamel using butter, flour, milk, half a litre of the cooking water, salt and pepper. Add the asparagus to the béchamel and keep cooking for another 5 minutes stirring constantly. Use the blender to smooth the mixture and then pour it through a fine strainer. Add the cream and allow it to cool. Place a roe dollop in each bowl and cover lightly with the asparagus soup.