Heat a frying pan and fry the chorizo for 2-3 minutes, stirring frequently.
Add the sliced cooked potatoes and the spring onion and cook gently, stirring occasionally, for five minutes.
Slightly crush the potatoes with a fork and mix well to combine the ingredients. Season, to taste, with salt and freshly ground black pepper.
To serve, place the chorizo and potato hash onto a serving plate and top with a poached egg.