Start by slicing the sesame-seed hamburger bun in half. This bun will cradle our roast beef perfectly. You can lightly toast the inside for added texture, but it’s not necessary.

Next, layer the paper-thin sliced roast beef onto the bottom half of the bun. The more beef, the better! It should be warm and inviting. If you’d like to elevate the flavor, consider heating the roast beef in a pan or microwave for a few seconds.

On top of the warm roast beef, place the slice of provolone cheese. Let it sit for a minute to allow the heat from the beef to melty the cheese slightly. Trust me, this step is key for a rich, melty goodness.

Now, take that delightful horseradish sauce and spread it on the top half of the bun. This will give each bite a kick that balances beautifully with the beef and cheese.

Finally, place the top half of the bun over the assembled ingredients. Press down gently to ensure everything melds together nicely.