Method

Grease the inside of four large ramekins with the butter. Crack two eggs into each ramekin and season with salt and pepper. Thoroughly fry the chopped Merguez sausage for 3-4 minutes and divide equally among the ramekins.
Individually cover the ramekins with foil and place them in a saucepan into which they fit snugly. Fill the pan with water to a level just 1cm from the top of the ramekins, heat until the water is simmering and cook for 10 minutes. Turn off the heat and leave to sit for a further five minutes.
Meanwhile, combine the harissa paste with a tablespoon of olive oil and a splash of water in a small bowl. When the coddled eggs have rested for five minutes, remove the ramekins from the water, uncover and drizzle with the harissa mixture. Garnish with yoghurt and a mint leaf and serve immediately.