Prepare the oven and baking pan.

Preheat your oven to 350°F (180°C) or 160°C for fan-assisted settings. Lightly grease a baking dish measuring 9×9 or 7×11 inches. Alternatively, a 9×13-inch pan can also be used.

Slice the rolls.

Using a serrated knife, carefully separate the tops of the Hawaiian rolls from the bottoms. Arrange the bottom halves inside the prepared baking dish.

Cook the beef mixture.

Heat the olive oil in a large, non-stick skillet over medium-high heat. Add the ground beef, diced onion, and minced garlic. Cook for 5–7 minutes, stirring frequently and breaking the beef into smaller crumbles, until it is fully browned.

Incorporate the seasonings and sauces.

Lower the heat to medium. Stir in the tomato paste, ketchup, Worcestershire sauce, yellow mustard, and chili powder. Mix thoroughly to ensure the beef is evenly coated with the flavorful sauce.

Simmer the mixture.

Pour in the water, stirring to combine. Reduce the heat to low and allow the mixture to simmer gently for 10–15 minutes, stirring occasionally. The sauce should thicken, and the flavors should meld beautifully.

Assemble the sliders.

Spread the prepared beef mixture evenly over the bottom halves of the rolls in the baking dish. Sprinkle the shredded cheddar cheese generously over the beef filling, then place the tops of the rolls over the cheese layer.

Add the finishing touches.

Brush the tops of the rolls with the melted butter. Sprinkle sesame seeds evenly over the buttered surface.

Bake the sliders.

Transfer the dish to the preheated oven and bake for approximately 15 minutes, or until the tops of the rolls are golden brown. Monitor closely to avoid over-browning.

Serve.

Remove the sliders from the oven and allow them to cool slightly before serving. Enjoy warm for the best flavor and texture.