Cook the onion in a little olive oil until softened. Add the chorizo and cook for a few minutes until it starts to crisp up. Tip in the tomatoes and simmer for 10 minutes then stir in half the coriander and season.
Heat the oven to 350°F Divide the sauce between two ovenproof dishes and make 2 dips in each. Crack the eggs into the dips. Put on a baking tray then bake for 15-20 minutes until the whites are set and the yolks are how you like them. Scatter with cilantro and serve with warm pitas.