Heat the oil in a nonstick ovenproof dish or roasting dish in a preheated oven, 200°C (400°F), Gas Mark 6, until hot.
Add the sausages and potatoes to the hot oil and turn to coat in the oil. Cook in the oven for 10 minutes.
Remove the dish from the oven, add the mushrooms and tomatoes and turn with the sausages and potatoes to coat in the oil. Return to the oven and cook for a further 10–12 minutes until the potatoes are golden and the sausages are cooked through.
Make 2 separate spaces in the baked mixture and break an egg into each. Return to the oven and cook for a further 3–4 minutes until the eggs are softly set. Grind over some black pepper and serve immediately.