Can I use a different type of bun?
Yes. Hoagie rolls, brioche buns, or regular hamburger buns work well, though onion buns provide the classic flavor match.
How do I keep the sandwich from getting soggy?
Toast the buns lightly and assemble just before serving. You can also brush the bun interior with melted butter to create a moisture barrier.
Can I make this ahead?
Prepare the beef and gravy up to 2 days ahead and refrigerate in an airtight container. Reheat gently on the stovetop before assembling sandwiches.
What cheese sauce can I substitute for nacho cheese?
Cheddar cheese sauce, queso blanco, or even melted cheddar cheese slices work as alternatives.
How many sandwiches does this recipe make?
This recipe makes 4 sandwiches using 14 oz of roast beef and 4 onion buns.