Yield: 4 servings
In a large pan over medium heat, sauté onions, celery and carrots in oil until soft.
Stir in beef or turkey; cook 5 minutes, stirring frequently, until meat is browned and crumbly.
Stir in remaining ingredients, except salt, pepper and hamburger buns.
Simmer, covered, 3 to 5 minutes.
Season to taste with salt and pepper.
Divide mixture evenly between hamburger buns to serve.