Heat oven to 350°F (for the bread bowls).
Season the beef with kosher salt and freshly ground black pepper. Set aside.
2 lbs. thinly sliced roast beef
Heat a large skillet over medium heat and add the oil and butter. Add the onions and green pepper and cook 3 minutes or until softened.
2 tbsp canola oil, 2 tbsp unsalted butter, 2 medium onions, 1 medium green pepper
Add sliced mushrooms and cook an additional 3 minutes or until mushrooms have softened. Add the garlic and cook another 30 seconds – just long enough for the garlic to bloom and become fragrant. Transfer the vegetable mixture to a separate bowl and set aside.
1 lb. button or cremini mushrooms, 2 cloves garlic
If needed, heat a little more oil to the skillet and add enough meat just to cover the inside of the skillet. Brown the beef on both sides, about 1 minute per side (the beef may still be a little pink inside). Transfer the beef to a paper towel-lined plate, and repeat until all beef is browned.
With the heat set to medium-low, slowly add the wine while deglazing (scraping the browned bits off) the pan. Add the beef broth, French onion soup and Worcestershire sauce. Stir well.
¼ cup red wine, 4 cups beef broth, 2 tbsp Worcestershire sauce, 1 10.5 oz French onion soup
Add the vegetables and the beef back to the pot and bring to a boil.
Reduce the heat to low and simmer 30-60 minutes to thicken the soup.
Add the heavy cream and simmer an additional 15 minutes, stirring often so the cream won’t scorch.
½ cup heavy cream
When ready to serve, fill each bowl with soup and top with 1 slice of provolone or mound with shredded provolone.
4 slices provolone cheese
Set oven to broil and place the bowls of soup on the middle rack. Watch the soup carefully, so the cheese doesn’t burn. Broil until the cheese has melted and just beginning to toast.