In a small bowl, mix together ketchup, brown sugar, tomato paste, mustard, vinegar, chili powder, and Worcestershire then set aside.

Brown ground beef, garlic, celery, peppers and onions in a large skillet.

Drain fat.

Add ketchup mixture and beef broth. Stir.

Cover and cook over low heat about 45 minutes or until veggies are tender.

Mix together cornstarch and water, add to meat mixture, cook until thick.

Serve on Buns

Turn Instant Pot to saute function.

In a small bowl, mix together ketchup, brown sugar, tomato paste, mustard, vinegar, chili powder, and Worcestershire then set aside.

Add ground beef and garlic to Instant Pot. Cook until almost done. Drain fat from beef.

Add celery, peppers and onion to beef in the pot (pot still on saute) and cook for 2 minutes.

Turn IP off and add ketchup and beef broth.

Cook on high pressure for 7 minutes. When timer goes off, do a controlled quick release.

In a small bowl, mix cornstarch and 2 Tbsp water. Turn pot back on to saute and add cornstarch mixture. Cook for 1-2 minutes until sauce becomes thick.

Stir and serve on buns.