Greek yogurtfor serving (omit to for vegan or dairy-free)
Chopped peanutsfor serving
Chopped fresh cilantrofor serving
Heat oil in a large pot over medium heat. Stir in the onion, then sauté until the onion is softened and translucent but not brown, 8 to 12 minutes.
Stir in the curry powder, salt, cinnamon, nutmeg, and bay leaf. Add the carrots and apples. Stir over medium heat for 2 minutes, then add 3 1/2 cups stock. Bring the mixture to a low boil, then reduce the heat to low. Cover and simmer until the carrots and apples are tender, 20 to 25 minutes.
Remove the bay leaf. Using a large slotted spoon, transfer the soup solids to a food processor or blender. Add peanut butter and process to a smooth puree, adding the remaining 1/2 cup stock as needed so that it blends easily (alternatively, you can use an immersion blender directly in the pot). Pour the puree back into the soup, then stir in the pepper. Serve hot, garnished with yogurt, peanuts, and cilantro.
Curried Carrot Apple and Peanut Soup will keep in the refrigerator for 5 days or frozen for up to three months, so it's a great make-ahead meal option too.