In 3-quart saucepan, heat oil over medium-high heat. Add onion and garlic; cook 3 minutes. Add zucchini, chiles, corn and tomatoes; cook 4 minutes. In small bowl, stir whipping cream and cornstarch until blended; stir into vegetable mixture. Add sour cream, salt and bouillion; cook and stir about 2 minutes until mixture boils. Stir in cilantro.