First make the herb garnish. Put the chilli and red onion into a glass bowl with the vinegar, 2 tbsps water, the salt and the sugar.
Put the spinach, onion and butter into a large frying pan. Place on a very gentle heat and cook, covered, for five minutes. Uncover, stir, and continue to fry for 5-10 minutes until all the water from the spinach has evaporated.
Add the cream, milk, a generous grating of nutmeg and the white pepper. Cook for a further 5 minutes, stirring occasionally. Check and adjust seasoning.
Make four wells for the eggs. Crack in the eggs and continue to cook for 5 minutes or until the egg whites have set. Cover with a lid to help this along.
Just before serving toss the dill and the chives with the chilli and red onion. Sprinkle over the spinach and egg and serve immediately.