Heat the oil in a saucepan over a medium heat, add the shallots, garlic and ginger and cook for a few minutes, stirring. Stir in the brown sugar and curry paste, then after another few minutes add the coconut milk and the kaffir lime leaves and stir through.
Add the duck thighs and cook on a low heat for 20 to 30 minutes with the lid on. Then add the duck breasts and cook with the lid on another 15 minutes or until tender.
Take out the duck thighs, slice them and return them to the curry.
Stir through the spinach along with the coriander, fish sauce and lime juice, cooking until the spinach has wilted.
Serve with fragrant rice such as jasmine, garnished with spring onions, chillies and lime halves.