Heat oil / ghee in a pan, fry the onions and green chilies for few seconds. Add the chopped spinach and toss till it looks wilt, then add garam masala and switch off. Let this cool completely and then grind in a mixie along with chopped coriander to a thick paste consistency. Combine wheat flour and salt together and add the spinach mixture to this and knead well to make a firm dough. Cover and let it sit for 15 minutes, then pinch some dough, roll out like disc (dusting with flour) about double the thickness of chapati. Heat a tawa, place the paratha and toast each side for about 2 to 3 seconds or until slightly browned. Rub with little ghee or butter on top and place them over a paper towel. Repeat the process for rest of the dough and serve hot with choice of gravy.