Heat the rapeseed oil in a large heavy-based pan over medium heat. Add the onion, garlic and chillies and fry for 3 minutes, or until softened.
Add the ginger, curry paste and aubergine and fry for a further 2 minutes.
Add the fish, coconut milk and 300ml water and bring to a boil. Reduce the heat and simmer for 10 minutes.
Add the spinach and stir through the sauce. Season with salt and bring to a boil.
Cook, uncovered for 2 minutes, or until just cooked through. Add soy sauce and fish sauce to taste.
Serving Suggestions: Sprinkle the coriander and serve with rice and lime to squeeze over.