Spray a lidded non stick frying pan lightly with the cooking spray.
Stir-fry the potatoes for 3-4 minutes over a high heat until starting to brown at the edges. Season with pepper, add 3 tablespoons of water and cover the pan. Cook, covered, for 5 minutes over a lowish heat, stirring once or twice, until the potatoes are almost cooked through.
Remove the lid, add the bacon and increase the heat under the pan to medium. Cook for 2 minutes, then add the mushrooms and cook for a further 2-3 minutes.
Make 2 spaces in the potato mixture and break an egg into each gap. Cover the pan again and cook gently for 2 minutes or until the eggs are cooked to your liking. Serve on warmed plates.