Sweet and Spicy Chili Barbecue Sloppy Joes

Ingredients

• 1 tablespoon olive oil
• 1 tablespoon yellow mustard
• 1/4 teaspoon black pepper
• 1/4 teaspoon kosher salt
• 1 pound ground beef
• 1/3 cup green bell pepper, finely chopped
• 1/3 cup onion, finely chopped
• 1 tablespoon Worcestershire sauce
• 1 cup sweet chili barbecue sauce
• 1/3 cup red bell pepper, finely chopped
• 1/4 teaspoon red pepper flakes, optional