Preparation Cook onion, salt, and pepper in oil in a 2- to 3-quart heavy saucepan over moderate heat, stirring occasionally, until softened, 4 to 5 minutes. Add curry powder and cook, stirring frequently, 2 minutes. Add tomatoes (with their juice) and broth and simmer, uncovered, 5 minutes. Stir hot water into peanut butter until smooth and add to soup. Simmer, uncovered, stirring occasionally, 5 minutes. Stir in cilantro before serving.
Preparation Cook onion, salt, and pepper in oil in a 2- to 3-quart heavy saucepan over moderate heat, stirring occasionally, until softened, 4 to 5 minutes. Add curry powder and cook, stirring frequently, 2 minutes. Add tomatoes (with their juice) and broth and simmer, uncovered, 5 minutes. Stir hot water into peanut butter until smooth and add to soup. Simmer, uncovered, stirring occasionally, 5 minutes. Stir in cilantro before serving.