
Heat oil in a large saucepan. Add onion and sauté over medium heat, stirring often until golden, about 2 minutes.
Add carrots, garlic and celery and sauté for another 8 minutes, or until softened.
Add vegetable broth and bring to a boil.
Turn down heat and add cubed squash. Simmer, covered, for 8 minutes, stirring occasionally.
Add beans, corn, thyme and pepper. Stir and simmer another few minutes, until squash is soft with a fork.