Cut the eggplant in half or quarters if they are larger and distribute throughout the pan. With the lid on, gently simmer for 15 minutes. If the sauce appears a little split at this stage, dont despair. Continue to simmer and the dish will become smooth and creamy. Turn the pieces of eggplant over, and continue to simmer for a further 10 to 15 minutes until the eggplant is just tender.