Heat up the oil in a large saucepan and add the onion, garlic, celery and mushrooms once hot
Fry for around 10 minutes until softened
Add the porcini mushrooms, almond milk, white beans, stock cube and salt + pepper, along with 300ml (1 ¼ cups) water
Bring to the boil and simmer on a low heat for around 15 minutes
Transfer the mixture to a food processor or blender (or use a hand-held stick blender) to whizz until completely smooth - add more water to thin out if necessary
Serve into bowls and scatter over chopped parsley, if desired
Leftovers keep covered in the fridge for up to a few days and also freeze well - reheat in a pot on the hob (stove) until piping hot - add a splash of water if necessary