1/2 ounce dried mushrooms–I used shiitakes but any kind works
1 large onion, chopped
1 leek, cut in half lengthwise, then sliced into half moons
1 carrot, diced
2 cloves garlic
1/2 cup pearl barley
Salt
1 quart good-quality beef broth
1/2 cup black or green lentils
1 teaspoon cider vinegar
Parsley, for garnish