When it is cold outside this is one meal I love to cook. It is quick and delicious. I also make it for Super Bowl Sunday almost every year.
First things first. Cut up a couple large yellow onions and toss them in a frying pan with a couple tablespoons of butter. Let the onions cook on low, stirring occasionally until they are all caramelized. They should be very limp and soft. Then add half a can of beef broth ( about a cup) and let it simmer for 5 - 10 minutes.
In the meantime, rub your steaks in your favorite steak rub. This time I used two sirloin tip steaks. To keep them tender don't overcook them. We like them pink inside. Then cut them in strips.
Slice your bread -- I used sub rolls that I bought in the bakery section of my local grocery store. Pile on your steak strips. Smother it in caramelized onions. and top with shredded mozzarella cheese. I am generous with the cheese. I lavish about 1/2 cup of shredded moz on each sandwich.
To really finish it off right, toast it under the broiler to melt the cheese and make it bubble. If you follow these step exactly (how can you not with all my very precise instructions) each bite will melt in your mouth.