Wash the asparagus. Peel lower halves, cut off woody ends briefly. Halve the asparagus. Shortly before serving, cook in lightly boiling salted water for about 12 minutes. Cook the pasta in boiling salted water for about 8 minutes.
Wash the fish and cut into large cubes. Bring the stock to the boil briefly. Let the fish simmer for about 5 minutes. For the sauce, heat the stock. Stir in sauce powder, bring to the boil briefly. Cut fat into small pieces. Gradually fold in the fat and add a little heat. Stir in saffron and yoghurt. Refine with lime juice.
Stir in sauce powder, bring to the boil briefly. Cut fat into small pieces. Gradually fold in the fat and add a little heat. Stir in saffron and yoghurt. Refine with lime juice. Serve asparagus, fish, sauce and pasta garnished with lime and chervil