Place the bacon under a preheated grill for 5-7 minutes until golden.
Meanwhile, poach the egg for 2-3 minutes in boiling water.
Heat the oil in a large frying pan and fry the mushrooms for 2-3 minutes, remove and add the tomato slices and fry for 2-3 minutes. Spread the ketchup on 2 slices of bread.
Place the bacon and egg on one slice and lay the other slice on top. Top with mushrooms and tomato and the place remaining toast on top and serve.