Add oil to a 3-quart pot over high heat. When the oil is shimmering hot, add onions and ginger. Stir and then add diced mushrooms. Cook for 2-3 minutes until the onions are translucent.
Add broth, soy or almond milk, chicken broth, miso, soy sauce, xanthan gum, salt, and pepper.
Allow the mixture to come to a boil. Add in salmon and turn down the heat to medium-low so that the broth is bubbling gently. Allow the salmon to finish cooking, about 2-3 minutes. When the salmon flakes easily with a fork, remove the pot from the heat. Stir in vinegar and the remaining green onions, and serve.
Tips And Tricks For Making Miso Soup With Salmon
Use the thickest milk you can find for this recipe.
For those who avoid soy, use whole milk, heavy whipping cream, almond milk or really anything else you prefer.
To make this recipe go even faster, cut the salmon while the rest of the ingredients are cooking.
Make a double batch to have the next day but do not freeze. This recipe doesn't freeze well because of the milk.
You could always use tofu in place of the salmon if you'd like to make this a vegan dish.