Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   2 1/4  pounds        calf or lamb's liver
                        oil or butter for frying
     1/2  cup           finest quality oil
   2      tablespoons   flour
                        flour for dipping
     1/3  cup           vinegar
     1/2  tablespoon    tomato paste + 1 cup water
     1/2  teaspoon      rosemary -- (opt.)
   1                    bay leaf
                        salt and pepper to taste
   1      cup           water -- (or more as needed)

Preparation:

Slice liver, dip slices into flour, fry in hot oil or butter, and place on a platter. Add the 1/2 cup oil to the oil in which you fried the liver, and when it is hot, slowly add the 2 tbs flour, stirring constantly with a wooden spoon until well blended. When the mixture is lightly browned, add the vinegar, tomato paste and water. Add rosemary, bay leaf, and salt and pepper. Cook the sauce for 5 to 10 minutes (but do not let it become too thick). Add liver to sauce; cook for 2 to 3 minutes longer. Serve hot or cold. NOTE: Liver prepared in this fashion will keep for several days, especially during the winter.