In 4-quart Dutch oven, heat oil over medium-high heat. Cook onion and garlic in oil 2 to 3 minutes, stirring frequently, until tender. Add squash, chili powder, cumin and salt; cook 1 minute. Stir in broth and green chiles. Heat to boiling; reduce heat to low. Cover; simmer 20 to 25 minutes or until squash is fork-tender.