Philly Cheesesteak

Ingredients

• • 1 1/2 lb (675 g) thinly sliced fondue beef
  • 2 tablespoons (30 ml) olive oil
  • 8 oz (227 g) white button mushrooms, thinly sliced
  • 1 large onion, thinly sliced
  • 1/4 cup (60 ml) chicken broth
  • 2 tablespoons (30 ml) Worcestershire sauce
  • 1 cup (250 ml) grated mozzarella or provolone cheese
  • 4 submarine buns, about 9-inch (23-cm) long
  • Iceberg lettuce, thinly sliced, to taste
  • Salt and pepper