Cook the Ground Beef:
In a large skillet over medium heat, cook the ground beef, breaking it apart with a spoon, until browned and cooked through. Drain any excess fat.
Sauté Vegetables:
Add the diced onion and green bell pepper to the skillet. Sauté until the vegetables are softened, about 3-5 minutes.
Add Garlic and Seasonings:
Stir in the minced garlic and cook for an additional 1-2 minutes until fragrant. Add salt, pepper, and chili powder.
Create the Sauce:
Pour in the tomato sauce, ketchup, brown sugar, Worcestershire sauce, and Dijon mustard. Stir well to combine all the ingredients.
Simmer:
Reduce the heat to low and let the mixture simmer for 10-15 minutes, allowing the flavors to meld and the sauce to thicken.
Adjust Seasoning:
Taste the Sloppy Joe mixture and adjust the seasoning if needed. Add more salt, pepper, or chili powder according to your preference.
Serve:
Spoon the Sloppy Joe mixture onto hamburger buns, and serve immediately.