Name: Mushroom Catsup
Ingredients: mushrooms; coarse sea salt

Mushroom Catsup

Ingredients

mushrooms
coarse sea salt

Directions

Pack mushrooms in layers in an earthen pot, sprinkling a little coarse sea salt between each layer.
Let them sit for about three hours.
Pound the mushrooms with a potato masher.
Let them sit for a day, stirring occasionally.

Recipe from a historical cookbook (Internet Archive).

Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.