1Heat a large skillet over medium-high heat. Add the ground beef and cook, breaking it apart as it browns, until no pink remains, about 5 minutes. Drain excess fat if needed.
2Add the diced onion and cook for 2 minutes, stirring occasionally, until softened.
3Stir in the minced garlic and tomato paste, cooking for 1 minute until fragrant.
4Add the ketchup, vinegar, brown sugar, worcestershire sauce, mustard, black pepper, and salt. Stir well to combine.
5Reduce heat to medium-low and simmer for 8–10 minutes, stirring occasionally, until the sauce thickens and flavors meld.
6While the sauce simmers, lightly butter the hamburger buns and toast them in a separate skillet or toaster until golden.
7Divide the beef mixture among the toasted buns and serve immediately.