Tavern sandwiches pile seasoned loose ground beef on soft buns for a classic Iowa family meal. This protein-rich, budget-friendly Midwest staple is simple, satisfying, and perfect for crowds.
Place a large skillet over medium-high heat and add the ground beef. As it starts to brown, break it up into small crumbles using a wooden spoon.
Add the diced onion. Cook for 5–6 minutes, stirring frequently, until the onion softens and the beef is mostly browned.
Lower the heat to medium. Drain excess grease if necessary. Stir in the yellow mustard, Worcestershire sauce, salt, and black pepper for even seasoning.
Pour in 1/2 cup water. Mix well, cover, and simmer the mixture over low heat for 10–12 minutes to keep the beef moist and let flavors meld.
Spoon the loose beef mixture onto soft hamburger buns while hot. Serve immediately for the best taste and texture.