Step 1 Place split peas into a large saucepan and cover with 4 cups cold water. Bring to the boil. Cook, stirring occasionally, for 20–25 minutes or until tender.
Step 2 Meanwhile, spray a large frying pan with oil and place over high heat. Cook lamb, in batches, for 5 minutes or until browned all over. Remove to a plate. Spray pan with a little more oil and cook eggplant, in batches, for 5 minutes or until browned and softened. Transfer eggplant to a bowl.
Step 3 Return pan to medium-high heat. Add onion and chilli. Cook, stirring, until softened. Add curry paste. Cook, stirring, for 1 minute or until fragrant.
Step 4 Add tomatoes and 2 cups cold water. Bring to the boil. Return lamb to pan and stir. Reduce heat to medium-low and simmer, covered, for 1 hour 15 minutes or until lamb is tender. Add peas, eggplant and spinach in the last 5 minutes of cooking time and stir to combine. Serve curry with yoghurt and roti, and top with coriander leaves.