Real Sloppy Joes

INGREDIENTS

• 1 Tbs. canola oil
• 1 yellow onion, diced
• 1 celery stalk, diced
• 1/4 cup finely diced green bell pepper
• 1 1/2 lb. ground beef
• 1 cup tomato sauce
• 1/2 cup ketchup-style chili sauce
• 1 Tbs. Worcestershire sauce
• 1 Tbs. Dijon mustard
• 1 Tbs. cider vinegar
• 1 Tbs. firmly packed light brown sugar
• 1 tsp. kosher salt
• 1/4 tsp. freshly ground pepper
• 6 sesame-seed sandwich buns, split