William Falconer,
Mushrooms: how to grow them
“ Mushroom Ketchup.—In making ketchup use the very best mushrooms, full grown but young and fresh, as it is highly important to secure fine flavor, and this we can not get from inferior mushrooms. Take a measure of fine fresh mushrooms and see that they are clean and free from grit; stem and peel them; cut them into very thin slices and place a layer of these on the bottom of a deep dish or tureen; sprinkle this layer with fine salt, then put in another layer and sprinkle with salt as before, and so on until the dish is full. ”
