01 -
Melt butter in a large pot or Dutch oven over medium heat. Add diced onion, green bell pepper, and mushrooms. Stir and cook until onions are translucent.
02 -
Incorporate chopped roast beef and minced garlic. Stir and cook for 2 to 3 minutes until garlic becomes fragrant.
03 -
Sprinkle flour over the mixture, stirring continuously. Cook for 3 minutes to eliminate raw flour taste.
04 -
Gradually pour in beef broth while stirring. Add half and half; stir until combined.
05 -
Add Worcestershire sauce, salt, and black pepper. Bring mixture to a boil, then reduce heat to medium-low. Simmer uncovered, stirring occasionally, for 10 minutes.
06 -
In a small bowl, whisk water and cornstarch together until smooth and fully dissolved.
07 -
Return soup to a boil. Stir in cornstarch slurry and continue boiling for 3 minutes until thickened.
08 -
Remove pot from heat. Stir in shredded provolone cheese until melted and smooth.
09 -
Ladle soup into bowls. Top with fresh chopped parsley and additional shredded provolone if desired. Serve immediately.