In a large saucepan, combine the mushrooms, broth, onion, garlic, and salt.
Cook for about 10 minutes on medium heat until mushroom have reduced in size and become soft.
Turn off the heat and remove about 1/2 cup of the mixture. Set aside.
Add in the coconut cream and using an immersion blender, blend the mushroom mixture until there are no chucks remaining. If it is too thick, add in a little broth at a time until desired consistency is reached.
Turn back on medium heat and add in mushrooms and thyme.
Add the arrowroot powder and whisk until there are no lumps. Stir until thick.
Store in fridge for up to one week.