Heat one and three-quarter cups of sugar with one cup of water to make a syrup of soft ball consistency. Keep warm.
Heat a pan. Add coconut and roast for two to three minutes. Add thickened milk and remaining sugar and cook, stirring till dry and lightly browned. Set aside to cool.
Take grated sweet potatoes in a bowl. Add refined flour and knead into a pliable dough.
Divide the coconut mixture and the sweet potato into sixteen portions each. Stuff each sweet potato portion with coconut mixture and shape into oblong croquettes. These are pulis.
Heat sufficient ghee in a kadai and deep fry these pulis on medium heat till golden. Drain and dip them in the syrup for fifteen to twenty minutes.
Serve at room temperature.