Season the chuck roast generously with salt and pepper.

Heat olive oil in a skillet over medium-high heat and sear the roast on all sides until deeply browned.

Transfer the roast to a slow cooker. Add beef broth, onion powder, garlic powder, Worcestershire sauce, balsamic vinegar, bay leaves, and thyme.

Cover and cook on LOW for 6–8 hours, until the beef shreds easily with a fork.

Remove the roast, discard bay leaves and thyme stems, shred the beef, and return it to the cooking liquid.

Melt butter in a skillet over medium-low heat. Add onions and a pinch of salt. Cook for 25–30 minutes until caramelized.

Stir together melted butter, garlic powder, parsley, and salt to make the garlic butter.

Keep Hawaiian rolls connected and slice the entire pack in half horizontally. Place the bottom slab on a baking sheet.

Layer roast beef, caramelized onions, and provolone cheese over the rolls. Bake at 350°F or broil just until the cheese melts.

Spread garlic aioli on the inside of the top slab, place it on the sliders, brush with garlic butter, and bake 5–7 minutes until warmed through.

Slice into individual sliders and serve warm.