Mushroom Ketchup

1-1/2 pounds mushrooms, firm and fresh 
1 large portobello
1-1/2 Tablespoons pickling salt 
3 cup hot tap water 
2 cups white wine vinegar 
3 large shallots, peeled or 1 small onion, peeled 
1 garlic clove, peeled 
10 whole allspice berries or 1/4 teaspoon ground allspice 
4 whole cloves 
3 large mace blades 
2 bay leaves 
1/2 teaspoon ground ginger 
1/2 teaspoon freshly ground pepper 
1/4 cup medium or dry sherry 

Clean mushrooms. Slice the mushrooms thin (a food processor fitted with the thin-slicing disc makes short work of this task) and mix them thoroughly with the salt in a ceramic bowl. Cover mushrooms with a cloth and let them stand 24 hours, stirring occasionally. They will become very dark (the finished ketchup will be approximately the color of black bean soup). 

Lift the soaked mushrooms from their liquid with a slotted spoon (this is to eliminate any grit that may be in the liquid) and place them in the container of a blender or food processor. Let soaking liquid settle for a minute or two, then carefully pour it over the mushrooms, stopping before any grit is poured out. Puree the soaked mushrooms, then pour the puree into a preserving pan. Without rinsing the blender container, puree the salted mushrooms; add this puree to that in the pan. 

Place about 1/2 cup of the vinegar in the blender and add shallots and garlic; process them to a puree. Add this puree to the mixture in the pan, together with the rest of the vinegar, the allspice, cloves, mace, bay leaves, ginger, and pepper. Bring the mixture to boiling over medium-high heat, lower heat, and simmer the ketchup, uncovered, stirring it often, for 1 to 1-1/2 hours, or until the tiny fragments of mushroom are very soft, almost jellylike, and the ketchup is thick. 

To test for correct consistency, pour a spoonful onto a saucer and let it stand 10 minutes, with the pot off the heat; if very little or no liquid seeps from the solids, the ketchup has thickened enough. If it does not pass this test, resume the cooking for as long as necessary. 

Press ketchup through a sieve to remove the bay leaves and whole spices, then puree it again, in batches if necessary, in a blender or food processor, running the machine until the texture is velvety smooth.  Return ketchup to the rinsed-out pan and bring it to a full boil again over medium-high heat, stirring it constantly. Stir in the sherry. 

Can in mason jars or store in the refrigerator.