01 -
Heat the butter in a large pot or Dutch oven over medium heat until fully melted. Add diced onion, green bell peppers, and mushrooms. Stir continuously and cook until the onions turn translucent.
02 -
Add the chopped roast beef to the pot and stir to combine. Add minced garlic and cook for 2 to 3 minutes until fragrant.
03 -
Sprinkle the all purpose flour over the mixture, stirring constantly. Cook for 3 minutes to develop the roux.
04 -
Gradually pour in the beef broth while stirring to avoid lumps. Add the half and half, Worcestershire sauce, salt, and pepper. Stir to incorporate all ingredients evenly.
05 -
Bring the mixture to a boil, then reduce heat to medium-low. Let simmer for 10 minutes, stirring occasionally to prevent sticking.
06 -
In a small bowl, mix water and cornstarch until fully dissolved.
07 -
Return the soup to a boil. While stirring, slowly add the cornstarch slurry. Continue boiling and stirring for 3 minutes until the soup thickens.
08 -
Remove the pot from heat. Stir in the shredded provolone cheese until melted and smooth. Garnish with fresh chopped parsley and additional shredded provolone as desired before serving.