In a small saucepan, bring 1 cup of the veggie broth to a boil. Turn off the heat. Add the dried mushrooms, thyme and 2 whole garlic cloves and stir. Let this sit for at least 15 minutes.
Heat a large soup pot over medium heat. Add the onions and cook for about 7-8 minutes, until they are browning and softening, stirring occasionally. Add a splash of water if they start to stick. Keep an eye on them.
Add the sliced mushrooms to the soup pot with the onions, and sauté for about 8-10 minutes, stirring often, until they have softened and browned. Deglaze the bottom of the pot with a splash of water as needed if things are sticking.
Place the mushrooms, thyme and garlic from the saucepan into a high-speed blender, along with the cashews. Blend, adding a splash of water if needed, until smooth and there are no chunks of cashews left. Set aside for now.
To the soup pot add the remaining 3 cloves of minced garlic, the black pepper, miso, salt, and a splash or two of water to help mix in the miso. Let this cook for another 2 to 3 minutes.
Add 4 cups of veggie broth to the soup pot and bring everything to a simmer, and then whisk in the cashew mixture from your blender.
In a small bowl, dissolve the arrowroot powder in the remaining 1 cup of broth, add this to the soup pot, and continue to stir. Cook for about another 5 minutes, until the soup thickens. Don’t let it boil or you’ll lose the special healing power of the miso!
Serve with crusty, whole grain bread or homemade croutons!
Tip: Add a few grinds of black pepper and a sprinkle of thyme over each bowl if you’re feelin’ it.
Arrowroot powder is a root vegetable—a tropical plant known as Maranta arundinacea—that is ground into a powder. It’s a great, healthy thickener for soups and sauces.