1. Preheat oven to 350°F (175°C).

2. Heat olive oil in a large skillet over medium-high heat.

3. Add ground beef and cook 5-7 minutes until browned; drain excess fat.

4. Add onion, bell pepper, and garlic; sauté 2-3 minutes until softened.

5. In a bowl, whisk tomato sauce, ketchup, brown sugar, Worcestershire sauce, mustard, and chili powder.

6. Pour sauce into skillet and stir to combine.

7. Simmer on low heat for 10 minutes, stirring occasionally, until thickened; season with salt and pepper.

8. Slice the block of Hawaiian rolls horizontally and place bottom half on a baking sheet lined with foil.

9. Spread the meat mixture evenly over the rolls.

10. Sprinkle cheddar cheese over the meat.

11. Place the top half of the rolls over the cheese layer.

12. Brush melted butter over the top and sprinkle with sesame seeds or parsley.

13. Bake for 10-12 minutes until cheese melts and tops turn golden.

14. Let sliders rest a few minutes; slice along roll lines and serve warm.