From: https://revolutionarypie.com/2013/03/14/mushroom-ketchup/

Ingredients

  • 2 pounds fresh mushrooms, cleaned and reduced to small pieces
  • 2 tbsp kosher salt – 2 bay leaves
  • 1 large onion, minced
  • zest of 1 lemon
  • 1 tbsp horseradish
  • 1/4 tsp ground clove
  • 1/2 tsp ground allspice
  • pinch of cayenne
  • 1/2 cup cider vinegar

Directions

  1. Combine the mushrooms, salt, and bay leaves in a large non-metallic bowl. Mash for a few minutes with a big spoon or masher. Cover and let sit overnight. The mushroom mixture will reduce in size considerably.
  2. Transfer the mixture to a Dutch oven and stir in the remaining ingredients. Bring to a boil over medium-high heat, reduce heat to low, and simmer the mixture for about 30 minutes, stirring often. The longer you cook it, the more concentrated the flavor will be. 1. Remove the pot from the heat and allow the mixture to cool, then place it in a large piece of muslin-type cloth or a double layer of cheesecloth, and squeeze the cloth over a bowl to remove as much liquid as possible. (I put a sieve under the cheesecloth, just in case.) 1. When you’re done squeezing, you should have about 2 cups of liquid — your ketchup! Store it in a glass bottle with a cork or other stopper.