Slow Cooker Cream of Mushroom Soup

I have hazy memories of a first date at a cozy French bistro with a bottle of red, a baguette, gooey cheese, and a satiny bowl of mushroom soup as a first course. I might not remember my date’s name, but the memory of that soup remains. This recipe recreates that magic by slow cooking roasted cremini mushrooms and dried porcinis — a far cry from the creamy mushroom soup found in a familiar red-and-white can.

Cooking earthy, umami-rich mushrooms low and slow with a splash of sherry supplies a background note of nutty sweetness that only a fortified wine can provide. Slow cooker soups run the risk of singing only one note, but by incorporating two types of mushrooms, a fortified wine, fresh herbs, and a squeeze of fresh lemon juice, all of the rich, earthy nuances of the mushrooms stand out.

This slow cooker soup actually starts with a trip to the oven. Fresh mushrooms have a very high water content, so a quick blast in a hot oven removes much of the excess liquid while concentrating their flavor and even caramelizing them slightly.

Dried porcini mushrooms have a delightfully strong and nutty flavor. We skip the standard pre-soak, instead rehydrating porcinis in the low and slow simmer of the slow cooker. Snip them down to size with a pair of kitchen shears before stirring them into the soup. Any flavor that would have been lost in a separate soaking liquid is preserved here, enhancing store-bought vegetable broth.

This slow cooker cream of mushroom soup is an ideal make-ahead addition to your dinner party menu. The mushrooms can be roasted a few days in advance, then refrigerated. Set the soup to slow cook as you ready the rest of the meal in anticipation of your guests’ arrival. It’s an elegant soup, perfect as a first course for the fanciest of dinner parties, but also a simple treat for yourself on a cozy evening at home.

The slow cooker is a handy tool for every kind of kitchen — including ones where vegetable-driven, plant-powered, meat-free food is the order of the day. In this series we’re sharing five essential vegetarian soups to make in the slow cooker.

We’ll show you how to come home to a simmering pot of lentils, a better-than-the-box vegetable broth, a luxurious cream of mushroom soup, a brothy vegetable soup for chilly nights, and a classic chili that’s perfect for busy weeknights or game day.