Heat 1-2 tablespoon of EVOO in a non-stick saucepan, saute onion and ginger for about a minute then add the chicken, season with salt and pepper and saute until lightly browned (you will see a slight caramelization). Pour in a quart of water (4cups). Season with patis (fish sauce). Cover and bring to a boil; lower heat and let simmer for 10 minutes, then add the chayote. Cover and simmer again until the chicken and chayote are tender, taste and adjust seasoning if necessary, then add in the chili pepper leaves, cover the pan; you may either turn off the heat now or let it simmer again for about 3 minutes more. Let cool a bit before serving.