Best Grilled Cheese Sandwich I Make

This has been a favorite of mine since I was young and my mother made them for me. For this one you need:
Bread of your choosing
Sliced Roast Beef
Sliced Swiss Cheese
Butter
Olive Oil
Sliced Onion
Sliced Mushroom

In spite the fact that it's tasty and so simple to make, I've never encountered anyone else that makes a grilled cheese sandwich this way.

I only use one slice of cheese in the video. My mother informs me that it's easier to keep the sandwich together with two slices of cheese, one on top and one on the bottom. It's good either way, but you get a more pronounced swiss flavor and easier to flip sandwich with two slices of swiss cheese.