In a large skillet over medium high heat, add the lean ground beef and the diced yellow onion.

Heat until the meat is completely cooked through and brown, and the onions are tender. While cooking the meat, use a spatula to ensure it is broken up into very small pieces. Once cooked, drain off any grease from the pan.

Lower the heat to medium. Add the beef broth, Worcestershire sauce, yellow mustard, brown sugar, apple cider vinegar, salt and black pepper.

Cook the mixture, stirring occasionally, for 10 to 15 minutes, or until most of the liquid is absorbed by the meat.

Turn off the heat.

For assembly, place a spoonful of the warm loose meat on the bottom of each slider bun.

Add a couple of dill pickle slices and a squirt of yellow mustard. Top with the top of the buns and serve warm.