There are few things in life more enjoyable than a mound of roasted mushrooms. Whether scarfed down hot or at room temperature, using a fork or a spoon, I can plow through them like nobody's business. The question is, how do you take those same mushrooms, with their intense, savory roasted flavor, and turn them into a rich, comforting soup? The slow cooker sure comes in handy at times like these.
I start my recipe by tossing mushrooms, onions, and garlic in a mixture of lemon juice, red wine vinegar, and olive oil—all flavors which mellow out over a long cook, but add their unmistakable brightness to the finished dish. From there, I spread them onto a rimmed baking sheet and follow our basic roasted mushroom technique, roasting the mushrooms for fifteen minutes, then draining off the liquid they expel and returning them to the oven in order to promote more rapid browning. (Don't worry, that liquid will make its way back into the soup soon enough. We don't want to waste flavor, now do we?)
Once the initial roasting step is done, I leave the rest of the work to the slow cooker. For liquid, homemade or store-bought low-sodium chicken stock or vegetable stock is a given for the backbone it adds. And where would creamy mushroom soup be without cream? (OK—mine uses half and half and heavy cream, but who's counting?)
Sherry and mushrooms are a classic combo and they work just as well in the slow cooker. Finally, a big dollop of sour cream adds more richness and tang.
After a few hours of slow cooking, the cream turns a rich, earthy hue and the soup is ready for its final trip to the blender. I prefer to keep my soup a little chunky, but if you like it completely smooth and creamy, it's just a matter of blending it for a bit longer. Make sure that you blend in batches and that you start your blender on its lowest possible speed if you want to prevent your kitchen from becoming a literal hot mess.
As slow cooker recipes go, this one requires a bit of advanced prep work, but it's lazy stuff: just toss the shrooms in the oven and go. It's the kind of work that deserves a reward. A hot bowl of creamy soup for dinner fits the bill nicely.