Cut the baguettes, spread a small amount of butter and fry in a dry pan.

First, fry the sliced ​​mushrooms and peppers on a little butter, and later add the chopped onion.

We set the roasted vegetables aside and start roasting the beef in a pan until it is slightly caramelized. In the end, we salt and season it to taste.

Mix the finished meat with roasted vegetables.

Spread the toasted baguettes with the mustard of your choice, place the hot meat mixture on them and cover with cheese.

When serving, you can sprinkle with the remaining spring onions.