Arrange the sliced prime rib on a plate and gently reheat it in a skillet over medium heat, just until warmed through and slightly crispy at the edges.
While the beef warms, split the buns and toast them lightly until golden and crispy on the cut sides.
Remove the beef from the heat once heated, and pile the slices onto the bottom halves of the toasted buns, spreading them out to cover the bread evenly.
Cover with the top halves of the buns, pressing gently to compact the sandwich slightly, ensuring the crispy edges and tender beef are balanced in each bite.
Serve the sandwich immediately, allowing the crispy bun and warm, tender beef to create a satisfying texture contrast.
