Mushroom soup is given a flavour boost by dried porcini alongside the usual fresh mushrooms, while chestnuts add a sweet nuttiness. Add bacon for smokiness or leave out for a vegetarian soup.
Put the dried porcini in a small bowl and cover with boiling water from a kettle. Set aside.
If including bacon:
Heat the oil in a saucepan and add the chopped bacon. Cook until starting to brown then add the butter.
If not including bacon:
Heat the oil and butter in a saucepan.
Add the onions and celery to the pan, season with a little salt and pepper and cook until they are starting to soften and brown (10-15 min).
Meanwhile, drain the porcini mushrooms, but save the soaking liquor. Chop the porcini finely.
Add the fresh mushrooms and the porcini to the pan, season with a little salt and pepper again plus the thyme. Cook, stirring regularly until the fresh mushrooms are starting to brown.
Stir in the chopped chestnuts until they are well combined with the rest of the ingredients.
Add the stock, the Balsamic, mushroom ketchup or Worcestershire sauce and the porcini soaking liquor (leave the last bit in the bottom of the bowl as it's usually gritty).
Put on a lid, bring to a boil then reduce the heat so that the soup gently simmers.
Simmer for 15 min.
Using a stick blender, off the heat blitz the soup but don't make it entirely smooth.
Stir in the cream and gently reheat if necessary.
Divide the soup between bowls and top with any or all of the serving suggestions.
Mushroom & Chestnut Soup should keep for three days in the fridge. Or freeze once cold.