Preheat the oven to 220C. Remove the stalks from the spinach and wash the leaves in plenty of cold water. Drain well and pat dry with kitchen pepper.

Heat 15ml/1 tbsp of the oil in a large frying pan and fry the onion until softened. Add the spinach and continue to fry until just wilted. Drain off any excess liquid.

Brush the pizza base with half the remaining oil. Spread over the tomato sauce or pizza topping, then top with the spinach mixture. Grate over some nutmeg.

Thinly slice the mozzarella and arrange over the spinach. Drizzle over the remaining oil. Bake for 10 minutes, then remove from the oven.

Make a small well in the centre of the pizza and drop the egg into the hole.