- Preheat the oven to 200°C/400°F.
- Using a wide, heavy bottomed frying pan high the steak slices briefly over a high heat in the oil. Remove from the pan and keep in a bowl.
- Add the onion and peppers and cook until soft, then add the mushrooms and cook until they've lost all their moisture. Add the steak pieces back in and season with garlic powder, salt and pepper.
- Take the pizza dough and divide into three equal chunks. Roll out into sausages then flatten and fill the middles with the steak mixture. Pinch up the sides to seal in the mix then lay them all together on a lined baking tray.
- Pinch the ends together and plait the three sausages together.
- Brush with egg and bake until risen and golden brown, roughly half an hour.
- Meanwhile, make the cheese sauce - toss the cheese in the cornflour and then add to a saucepan with the evaporated milk. Heat the mixture gently, stirring all the time, until the cheese has melted and the sauce begins to bubble.
- Serve with the plait.