Cut 10 g of the butter into small cubes and place them in the freezer.
Peel and finely chop the shallots, then gently sweat them in 5 g butter until soft and translucent. Deglaze with 100 ml white wine and reduce the liquid by half.
Add the fish stock and cooking cream. Let the sauce simmer gently for five minutes.
Split the vanilla pod lengthwise and scrape out the seeds; add them to the sauce. Blend the sauce with a hand blender. Add the saffron and allow to simmer for a further 10 minutes.
Dissolve the cornflour in a little bit of water and stir it into the sauce.
Lightly whip 2 tablespoons of cream. Warm the plates in the oven at 100°C.
Slice the asparagus tips lengthways into very thin strips and blanch them.