Heat olive oil in a heavy based saucepan over medium heat. Add onions, garlic and ginger and cook for 4 minutes. Add mustard seeds and a large pinch of salt and stir, then add dried chillies, remaining spices and sugar and cook 1 minute.
Add tomatoes and stock and simmer over low heat for 8-10 minutes. Add spinach and yoghurt and cook for a further 8-10 minutes. Add eggs and check seasoning. Stir through coriander leaves. Serve!