• Pre-heat oven to 350°F degrees.

CARAMELIZE THE ONIONS

• In a large skillet over medium-low heat, melt 2 tbsp of butter. Add the onions and toss to coat. Cook, stirring occasionally, for about 15 minutes until the onions are soft and browned. Make sure they don't burn.
• Stir in the fresh thyme, and kosher salt. Remove from the heat and set aside.

MAKE THE GARLIC BUTTER SAUCE

• In a small saucepan over medium heat, melt the remaining butter. Whisk in 1 tbsp of dry au jus mix, Worcestershire sauce, and minced garlic. Cook for 1-2 minutes until well combined.

ASSEMBLE AND BAKE THE PRIME RIB SLIDERS

• Cut the slider rolls in half horizontally, keeping the individual rolls attached.
• Place the bottom half of the slider bread on a greased sheet pan or baking dish. Top with 6 slices of cheese, sliced prime rib, caramelized onions, and the remaining slices of cheese. Place the top of the rolls on the sliders.
• Evenly brush the tops of the sliders with the garlic butter sauce.
• Cover with aluminum foil and bake for 15 minutes. Remove the foil and bake for another 10 minutes, until the cheese is melted and the prime rib is reheated throughout.
• Let the sliders rest for 5 minutes before slicing and serving. Serve with dipping cups of au jus sauce.

MAKE THE AU JUS

• While the sliders are baking, add the remaining packet of au jus mix to a small saucepan over medium heat. Add the cold water amount listed on the au jus package and whisk. Bring to a slow boil, then simmer until ready to serve.