Grate half the onion and add to a bowl with the lamb. Season well and mix together. Use your hands to shape into 12 small balls, each about the size of a golf ball. Finely chop the remaining onion.
Heat the oil in a large, deep frying pan. Add the meatballs and cook for about 3 minutes on each side until golden all over. Then add the chopped onion, garlic and ginger to the pan and cook for a couple more minutes until softened.
Stir in the ras el hanout, then pour over the tomatoes and 200ml (7fl oz) water. Bring to the boil, then simmer for 20 minutes until the meatballs are cooked through.
Make 4 little hollows in the mixture and crack an egg into each one. Cover the pan with a lid or piece of tin foil and leave the eggs to poach for about 5 minutes, until the whites are cooked.