In a large skillet over medium heat, add the ground beef and chopped yellow onion. Season with salt and pepper to taste. Cook until the beef is browned and the onions are soft, about 5-7 minutes. Use a spatula to break up the beef as it cooks.
Once the beef is cooked through, drain any excess fat. Then, stir in the barbecue sauce, ketchup, Dijon mustard, and Worcestershire sauce. Mix well and let the mixture simmer for about 5 minutes, allowing the flavors to meld together.
While the beef is simmering, preheat your oven to 350°F (175°C). Cut the Kings Hawaiian rolls in half horizontally, keeping the tops and bottoms connected. Place the bottom half of the rolls in a baking dish.
Spoon the Sloppy Joe mixture evenly over the bottom half of the rolls. Sprinkle the shredded cheddar cheese generously over the meat mixture. Place the top half of the rolls on top.
In a small bowl, mix the melted butter with a pinch of salt. Brush the tops of the rolls with the melted butter and sprinkle with sesame seeds if desired. Bake in the preheated oven for about 15-20 minutes, or until the cheese is melted and the tops are golden brown.
Remove the sliders from the oven and let them cool for a few minutes before slicing them apart. Serve warm and enjoy the deliciousness of your homemade Sloppy Joe Sliders!
