If you plan on using your own homemade rolls, make sure you have already prepared those ahead of time, bake them as normal, but maybe cover the rolls the last 5-10 minutes of baking so that the tops don't brown as much since you'll be baking them again in this recipe.

Preheat your oven to 350°F. Spray a 9×13 pan or casserole dish with cooking spray (or line with parchment for easy removal). Set aside

Using a sharp serrated knife, slice the entire sheet of rolls in half horizontally—keeping them together—so you have a top layer and a bottom layer.

Place the bottom half into your prepared pan.

In a small bowl, stir together the mayonnaise and yellow mustard.Spread half of the mixture onto the bottom layer of rolls.

Add half of the Swiss cheese in an even layer (trim a slice in half if you need to).

Melt the butter in a microwave-safe bowl.Let it cool for a minute, then whisk in Worcestershire, Dijon, and onion powder.

Slowly pour the melted butter mixture over the top of the rolls. Then use a pastry brush to coat everything evenly.I also like to carefully slice between the rolls before baking so the butter soaks into every edge.

Cover loosely with aluminum foil and bake in a preheated oven for 20 minutes.

Remove the foil and bake another 3–5 minutes, just until the tops are golden brown, lightly crisp and the cheese is melty.

Serve warm—straight from the pan is the best way. I love using parchment paper to line my pan because it makes it easy to transfer them to a pretty dish for serving when I am taking them to parties.