In a large soup pot, add 1 tbsp oil (preferably olive, avocado or coconut oil). Saute onion, celery and garlic until fragrant. About 5 minutes.
Roughly chop your mushrooms and add to the pot. Cook until they release their moisture and begin to brown, about 8-10 minutes.
Stir in the dried thyme and cook for another minute to let the flavours meld.
Pour in the broth or water + bay leaf. Let it cook about 15-20 minutes, allowing the flavours to deepen.
Once the soup has simmered and the mushrooms are tender, remove bay leaf (if used) and use an immersion blender or a regular blender to blend the soup to your desired consistency.
Return the pot to low heat and stir in the coconut milk and nutritional yeast.
Taste the soup and adjust the seasoning with salt and pepper if needed.