Cook the sausages, or you can pre cook them in advance
Lightly spray 2 large ramekins or individual pie dishes with low calorie cooking spray
Heat a frying pan over a medium heat, spray with low calorie cooking spray, then add the onion and mushrooms. Gently fry until they start to colour
Divide the sliced sausage, onion and mushrooms evenly between the two dishes.
Spoon the chopped tomatoes over the onions and mushrooms
Season with a little sea salt and freshly ground black pepper, then top with the grated cheese
Crack an egg on the top of each one, spray with a little low calorie cooking spray and sprinkle with a bit more salt and pepper
Either bake in the preheated oven for 15 - 20 minutes or microwave on high for at least 60 - 90 seconds (don't forget to cover with cling film in the micro wave). Make sure the egg is cooked as you like it and serve