Finely chop the onion and bell pepper, and mince or grate the garlic.
Heat olive oil in a large skillet over high heat. Add the ground beef, season lightly with salt, and cook until browned, breaking it up as it cooks. Transfer the beef to a bowl.
Lower the heat to medium and add the onion, bell pepper, and garlic to the same skillet. Season with salt and pepper and cook until softened.
Stir in the chili powder and paprika and cook briefly until fragrant.
Return the beef and its juices to the skillet. Add the tomato sauce, ketchup, water, mustard, Worcestershire sauce, and brown sugar.
Bring the mixture to a gentle simmer, scraping up any browned bits, and cook until thick and saucy.
Taste and adjust seasoning as needed.
Spoon the mixture onto toasted buns and top with pickle chips if desired. Serve warm.