Heat the oil in a large skillet over medium-high heat.
Add the mushrooms, onion, bell pepper, celery, carrot, garlic, ground turkey and ground beef; sauté 5 minutes or until the meat is browned, stirring to crumble. Spoon out any accumulated fat, and discard.
Stir in the ketchup and remaining ingredients (except buns); bring to a boil. Cover, reduce heat, and simmer for 20 minutes, stirring occasionally.
Serve on toasted hamburger buns.
Notes
These are good with a slice of sharp cheddar melted on top too. Add calories in!