Here are two methods of making mushroom soup – the first with dried mushrooms and the second with fresh. Both are excellent, the fresh mushroom one being the easier.
You will need:
Mushrooms, dried or fresh
White sauce or plain flour
Pepper and salt
A chicken stock cube
Dried mushrooms impart, for less cost, more taste to a soup than the fresh variety, though if using the latter their taste will be enhanced by turning them into soup.
Buy a small handful of dried, sliced mushrooms (porcini are best). Shake them well in a sieve to rid them of sand. Soak them for 24 hours. Extract the mushrooms and, with knife or scissors, cut them into small pieces. Keep the (brown) liquid, but decant it off any sand that has fallen to the bottom of the water.
Now make a white sauce using butter, flour, milk, water and the liquor in which the mushrooms were soaked Add the mushroom pieces.
You will want to add extra liquid in the form of milk, or a dissolved stock cube or two, to give the soup the desired consistency and extra taste.
Season as thought necessary - and serve. This soup, like the one below, which uses fresh, white, button mushrooms, is even better the following day.
Using fresh mushrooms:
There is hardly a simpler or more economical way to make a glorious soup than the following way when using fresh, white, button mushrooms.
Cut up a good size onion as finely as possible. Then do the same with fresh mushrooms – say as many as you can hold in cupped hands (or 250g). Both of these operations take time – but it is worth it.
In a saucepan melt a good lump of butter, and into it stir your chopped onion. Cook this slowly until the onion is transparent. Now add the mushroom bits. Continue stirring the mixture over heat, sweating them all together. Add pepper, salt and a sprinkling of flour – a dessert spoon at the most. Stir this. The mixture will now be quite tacky. Crumble in a chicken stock cube. Now add plenty of milk (1 1/2 pints will do), stir, and allow the soup to boil very, very slowly for, say 20 to 30 minutes. That’s it. And the result will be quite delicious, taste as if you have used cream, and be even better the next day. So make it the day before wanted if possible.