Ingredients:
1 lb (450 g) ground beef
1 tbsp olive oil or butter
1 small onion, finely diced
1 green bell pepper, diced
1 red bell pepper, diced (optional)
2 cloves garlic, minced
1 tbsp Worcestershire sauce
1 cup beef broth (or 1 beef bouillon cube + 1 cup water)
1 tbsp cornstarch + 2 tbsp water (slurry, for thickening)
Salt & black pepper to taste
1 cup provolone cheese (shredded) or mozzarella
4–6 sandwich buns (hoagie rolls or hamburger buns work great)
