Boil the potatoes in boiling water for 8-10 minutes until just tender, drain and allow to steam dry.
Meanwhile, heat the oil in a large frying pan and fry the potatoes for 5 minutes, add the onion and fry for a further 5 minutes until golden. Stir in the tomatoes, walnuts and parsley and cook for a further 3-4 minutes.
Place the spinach in a large bowl and microwave on high for 2-3 minutes until just wilted, add to the pan and season with black pepper.
Poach the eggs in boiling water for 2-3 minutes and serve on top of the hash.