Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   4                    locus fish fillets -- or white firm-flesh
   1      pound         Jerusalem artichokes
   2      tablespoons   olive oil
     1/4  cup           white wine
   1      teaspoon      fresh rosemary -- chopped
                        juice from 1 lemon
   1 1/2  cups          heavy cream
                        salt and pepper

Preparation:

Peel and thinly slice the Jerusalem artichokes. Melt the butter and olive oil together in a pan. Fry the fish fillets 3 minutes on each side. Set aside, keep warm. To the same pan add the wine, scraping the bottom of the pan. Add rosemary, lemon juice, Jerusalem artichokes, heavy cream, salt and pepper. Cook until the Jerusalem artichokes soften and the sauce is reduced to a half, about 1 to 1 1/2 hour. Transfer the fish fillets to serving plates, pour the sauce over the fish, and garnish with rosemary sprigs.