Season the steaks with sea salt and black pepper. Rub with a little olive oil.

Heat a wide frying pan on high. Cook the steaks for three to four minutes on each side, depending on thickness. You need them to be medium rare and nicely coloured on the outside. Set aside on a plate to rest, covered with foil.

Add a splash of oil to the pan along with the onions, sauté for a few minutes before adding the peppers. Cook until the onions are nicely softened and the pepper still retains a little bite. Season with a splash of Worcestershire sauce. Place the onion mixture into a roasting tin. Fry the mushrooms in the hot pan till they are nicely coloured. Add them to the onion mix.

Preheat the grill to high. Warm the bread rolls slightly in the oven. Thinly slice the steak and combine it with the onion and mushrooms. Layer the cheese slices over the top. Place the roasting tin under the hot grill and cook for five to ten minutes until the cheese is melted and bubbling. Quickly scoop the mix into the warm bread rolls and serve with a little more Worcestershire sauce, tomato ketchup and mustard on the side.