Ingredients
1 pound ground beef
1 cup beef broth
1/2 cup onion, diced
1 tablespoon Worcestershire sauce
1 tablespoon spicy brown mustard
1/4 teaspoon ground black pepper
1 tablespoon sugar
1 tablespoon yellow mustard
4 hamburger buns, split
8 dill pickle slices
Directions
1. Heat a large skillet over medium-high heat, and cook and stir until the beef is crumbly, evenly browned, and no longer pink. Drain and discard any excess grease. Stir in the beef broth, onion, Worcestershire sauce, brown mustard, pepper, and sugar. Bring to a boil, then reduce heat to low, and simmer uncovered until the liquid has evaporated, about 15-20 minutes. Stir every 5 minutes.
2. Preheat oven to 300 F.
3. Spread the desired amount of yellow mustard on the top half of each bun. Place 2 pickle slices on the bottom half, then spoon 2 to 3 tablespoons of the ground beef mixture over, and top with the other half of the bun to make a sandwich. Repeat until all the sandwiches are complete.
4. Wrap each sandwich individually with aluminum foil and place on a baking sheet. Bake in the preheated oven until the bread is warmed through, about 10 minutes.