Method;
Heat oil in soup pot over medium heat. Sauté onions, fennel and carrots till onions are translucent, about 5 minutes. Add red pepper and sauté another 5 minutes. Add tomatoes, water, salt, pepper and cayenne, and cook for 20–30 minutes, or until carrots are soft. In a small saucepan, heat broth to boiling. Turn off heat and whisk in peanut butter; pour this into a blender and add about half of the cooked soup. Blend until smooth, and pour back into soup pot. Stir to combine and add lime juice. Garnish each serving with lime zest and scallions.