Heat the butter in a frying pan, add the leek and chilli flakes and cook over a medium-high heat for 4–5 minutes until softened. Add the spinach and season well, then toss and cook for 2 minutes until wilted.
Make 2 wells in the centre of the vegetables and break the eggs into the well. Cook over a low heat for 2–3 minutes until the eggs are set. Spoon the yogurt on top and sprinkle with the paprika. [please check photo – do you make 2 wells in mixture, one for each egg?]