Coat a large Dutch oven with cooking spray; place over medium-high heat until hot. Add steak; cook until browned on all sides, stirring frequently. Add onion and next 9 ingredients, stirring well to combine.
Bring to a boil, cover; reduce heat and simmer 1 hour. Add pumpkin and continue cooking another 30 minutes. Add mixed vegetables. Cover and simmer 10 more minutes or until steak and vegetables are tender. Remove bay leaf and ladle into bowls.