Slow Baked Wild Mushroom Soup

Mushroom Barley Soup Ready to Go into the Oven
Photograph by A. Schloss

Slow cookers are unrivaled for soup. So in Cooking Slow, a book that includes lots of slow cooker techniques and recipes, but emphasizes slow cooking on the range and in the oven, I didn't include many soup recipes (the index lists only four). For the remainder of this winter I mean to fill the gap. Any soup that can be made in a  slow cooker can also be cooked in a low oven (200°F/95°C). Just bring everything to a simmer on top of the stove, cover the pot and throw it in a preheated oven. Return 5 to 8 hours later and dine.


As snow continued to pile up last week I put on a pot of one of our favorite winter soups. Its an upscale take on classic mushroom barely, dressed up with a combination of dried wild mushrooms and fresh exotic ones.  Most of the fresh mushrooms sold as “wild” in your supermarket are actually cultivated mushrooms, similar to the common white button mushroom, but because they have more flavor, a meatier texture, and are generally darker in color, we use them like the foraged wild mushrooms they resemble.

The parent recipe for this soup comes from Art of the Slow Cooker and calls for wild rice, rather than barley. Switching to the more populist and starchier grain helps to naturally thicken the broth and makes the finished soup more robust.  

Wild Mushroom Barley Soup

Ingredient Set-up (L to R, Bottom to Top) - Chopped Veg, Sliced Cremini, Parsley, Canned Tomato, Garlic, Chef Salt, Dried Porcini, Pearl Barley, Beef Broth
Photograph by A.Schloss

Makes 6 servings

1 tbsp extra-virgin olive oil

1 large onion, cut into 1/2-inch/1 1/4-cm dice

1 large carrot, peeled and sliced 1/4 inch/6 mm thick

1 parsnip, peeled and sliced 1/4 inch/6 mm thick

1 large celery rib, sliced 1/4 inch/6 mm thick

1 lb/454 g cremini (baby portobello) mushrooms, sliced

2 garlic cloves, finely chopped

1 tbsp Truffle Herb Chef Salt

6 cups/1.4 l mushroom broth, vegetable broth, or beef broth

1/2 cup/100 g barley

1/2 oz/15 g dried wild mushrooms, any type, minced

1 can (14.5 oz/412 g) diced tomatoes, not drained

1 tbsp chopped fresh Italian (flat-leaf) parsley, or chives

Preheat an oven to 200°F/95°C

Heat the oil in a large Dutch oven over medium-high heat.  Add the onion, carrot, celery, and cremini mushrooms and sauté until the vegetables brown lightly, about 6 minutes. Add the garlic and Chef Salt and cook for another 30 seconds. Add the broth, barley, dried wild mushrooms, and tomatoes and bring to a boil. Cover and bake until the soup is fragrant and the barley is tender, 5 to 8 hours.

Stir in the parsley and serve.

Like most soups, this one improves with age; for the best flavor prepare a day or two ahead, or cook overnight and refrigerate until dinner. As the soup sits, the barley will absorb more of the broth, so you might want to add a bit more broth when you reheat the soup.

Timing 
Prep: 10 minutes

On the stove top: 10 minutes

In the oven:  5 to 8 hours