Eggplant stew with potatoes takes 10 to 15 minutes. Hopefully, the potatoes and eggplant are stewed more rotten paste, then the stewing time will be slightly longer. Meanwhile, it is also common practice to turn down the heat after boiling over high heat, so as to better retain the original flavor of the ingredients. Some practices will be in the high heat boil and then turn to low heat stewing 10 ~ 15 minutes, during the seven or eight minutes when the lid to break the potatoes to achieve a better texture. There are also practices that recommend covering the pot with a lid and turning it to low heat to keep it open, simmering for 20 minutes until the soup becomes thick and the ingredients are cooked through. Adjust according to personal taste and cooking method. During the cooking process, you can taste and adjust the heat at the right time to achieve the best flavor.