In a medium pot, or deep skillet, add the mushrooms, garlic, thyme and a couple drops of water to prevent sticking. Sauté until the mushrooms are reduced, approx. 4 minutes.
Add the broth, miso paste and lemon juice and bring to a low boil, cooking for about 5 minutes. Turn off the heat, add the milk, and then use an immersion blender to puree your soup OR transfer to a blender. Taste and add salt and pepper, only if needed, and serve with crusty bread.
Do not salt your soup before tasting, once pureed. The miso paste and vegetable broth add a fair bit of saltiness. Once blended, taste the soup and add some, only if needed.Use low sodium vegetable broth, or use a mix of regular broth and water if you don't have low sodium on hand. You can always add more salt if needed, but you cannot remove.If you don't have an immersion blender, carefully transfer the soup to a blender and process until smooth. Use extreme caution when blending hot liquids, don't overfill your blender and work in batches, as needed!Leftovers keep refrigerated for up 4 days or freeze for up to 3 months.