Soak the cashews in hot water for 20 minutes then drain.

Add the cashews, water and lemon juice to the blender and process until silky smooth. Refrigerate until needed.

Slice the leek in half lengthwise then chop it up into small pieces. Place in a bowl and cover with cold water. Agitate the water to loosen up any dirt trapped between the layers then allow to sit undisturbed for 10 minutes.

Preheat a heavy bottom soup pot over medium heat. Scoop the leeks out of the water and transfer them to the soup pot. Add a pinch of salt and chili flakes and sauté the leeks until wilted.

Stir in the celery and mushrooms and sauté for a few more minutes until the mushrooms have released all their water.

Stir in the tomato paste, spices, thyme and tamari and simmer another minute or so then add the barley.

Combine the porcini mushroom powder and the water to create the stock.

Pour the mushroom stock in the pot over the barley and bring to a constant simmer. Cover with a lid and cook for 45 minutes to one hour until the barley is cooked through.

Pour in half of the cashew sour cream, taste and add more to your liking. Serve hot with extra red pepper flakes, chives, parsley or dill.