I found the following few recipes online but what I found really useful is a science project. A group of secondary students in Hong Kong had investigated the optimal temperature, ph level (aciditiy) and other factors for making this traditional dessert. To me, it's like a myth buster and truly enlightening. The pdf file can be found here. Other recipes I found online include: Magic ginger milk pudding, Ginger Milk Pudding, a Natural Custard by Taste Hong Kong, Ginger Milk Pudding by Kitchentigress, Wikipedia: Ginger milk curd
I have then experienced a bit to find the optimal temperature & ingredient ratios via 4 different attempts (using same kind of milk, sugar & the same knob of ginger).