Luke Brown on Instagram: "#sponsored Roast Beef sandwiches made with @arbys Horsey sauce won’t disappoint! This is the best way to use any leftover Prime Rib Roast from all of those holiday parties! INGREDIENTS 6 lb 5 oz Prime Rib Roast Salt, pepper, garlic powder 3 sticks of butter, softened 3 tbsp minced garlic 1 heaping tsp each rosemary and thyme 2 tsp onion powder 2 tsp dried parsley Au Jus gravy packet Hoagie rolls Arby’s Horsey Sauce Provolone cheese Crispy fried onions INSTRUCTIONS Seaso