When some people want to thicken a soup, they add flour or cornstarch. Others might add milk or cream. I prefer to add more of the main ingredient: I use probably double the amount of mushrooms here compared to what you’ll see in a “normal” recipe. The sheer volume makes the soup thick without adding anything that’s bad for you. Best of all, it adds even more mushroom flavor.
I went heavy on the garlic in this recipe because I wanted to be able to taste it. This is still a very mushroom-forward dish, but the roasted garlic notes are unmistakable. Use half as much garlic if you want the garlic to be more subtle.