Wipe mushrooms clean with a damp cloth or brush.

Slice mushrooms thinly and mix with pickling salt in a ceramic bowl.

Cover and let stand for 24 hours, stirring occasionally.

Combine dried boletus mushrooms with hot water and let stand until soft.

Lift soaked mushrooms and puree in a blender.

Pour soaking liquid over the pureed mushrooms, avoiding any grit.

Puree the salted mushrooms and add to the pan with the boletus puree.

Puree shallots and garlic with some of the vinegar and add to the pan.

Add remaining vinegar, allspice, cloves, mace, bay leaves, ginger, and pepper to the pan.

Bring to a boil, lower heat, and simmer for 1 to 1.5 hours, or until thickened.

Test consistency by placing a spoonful on a saucer; it should not release much liquid.

Press ketchup through a sieve to remove spices and bay leaves.

Puree again until smooth.

Return ketchup to the pan and bring to a full boil.

Stir in the sherry.

Ladle into hot, clean canning jars, leaving 1/4 inch headspace.

Seal jars with new lids and process in a boiling-water bath for 15 minutes.

Cool, label, and store the jars. Let mellow for a few weeks before serving.