Heat olive oil in a large skillet over medium heat.
Add diced onions, green bell peppers, and mushrooms; sauté until softened, about 5 minutes.
Add ground beef to the skillet and cook until browned, breaking it apart with a spoon.
Pour in beef broth and worcestershire sauce; stir to combine.
Season with salt and pepper to taste.
Simmer the mixture until the liquid reduces slightly, about 5 minutes.
Divide the mixture into 4 bowls.
Top each bowl with a slice of provolone cheese.
Cover and let the cheese melt before serving.