In a skillet, cook the meat over medium heat until it is almost browned, then add the onion, green pepper and celery. Cook on medium-low until onions are clear and vegetables are crisp-tender, 5-7 minutes.
Add all remaining ingredients to the skillet and simmer for 30 minutes. Serve over hamburger buns, or store in refrigerator or freezer for re-heating later.
Notes
Meat mixture can be stored in the refrigerator for 3 days or in freezer bags in the freezer for up to 6 months. Serve on slider buns for appetizers. Kids also love sloppy joes on slider buns for their meal!