Carrot-Ginger Soup

Carrot-Ginger Soup
2-inch piece fresh ginger, peeled
4 large shallots, peeled and cut in half
Zest of 1 large orange
2 pounds carrots, peeled and cut into 1-inch pieces
3 large potatoes, peeled and cut into 1-inch cubes
6 cups vegetable broth
1 cup orange juice5-10 drops hot pepper sauce, or to taste2-3 tablespoons soy sauce, or to taste
Plain yogurt or sour cream, for garnish (optional)Combine the ginger, shallots and orange zest in a food processor and pulse until finely chopped, about 10 seconds. Transfer the mixture to a slow cooker. Add the carrots, potatoes, broth and orange juice.Cover and cook on high for 2 hours, or until the vegetables are very soft.Use an immersion blender to puree the soup in the slow cooker, or transfer it in batches to a blender. Season the soup to taste with hot pepper sauce and soy sauce.Serve the soup garnished with a dollop of yogurt or sour cream.Serves six to eight.Adapted from "Slow Cooker Cooking" by Lora Brody (2001 Morrow)