Melt butter in a large skillet over medium heat.
Add sliced onions, garlic and 1/2 tsp Black Pepper and sautee until tender.
Remove onions from skillet, leaving remaining butter in pan. Set onions aside.
Add flour to pan and 1-2 tablespoons of beef broth and scrape and stir to make a paste,
Add Worcestershire and remaining broth and bring to a boil.
Reduce heat and simmer for 15 minutes.
Split rolls and toast lightly.
Add beef to pan and allow to warm for 5 minutes.
Place beef on bottoms of rolls.
Top each with sauteed onions.
Cover each with 2 slices of cheese.
Place in oven for several minutes to melt cheese.
Place tops on each sandwich and plate.
Fill ramekins/small bowls with juice from skillet and serve with sandwiches.