Add the butter or ghee to the pan till dissolved.
Add the onion to the pan, saute until softened about 5 minutes.
Add the garlic and saute for anther minute stirring often.
Add the mushrooms, herbs, salt and pepper. Stir.Cover and simmer till the mushrooms cook down and give off juices. Pour some bone broth or water in a bowl, add the flour to it and stir constantly with a whisk till the mixture smooths.
Add the mixture together with the rest of the broth/water to the mushroom pan.
Cook for 10 minutes or until the mixture is gently thickened, stirring often.
Add the coconut aminos and sour cream if using; also extra herbs or salt/pepper if desired to the taste.