In a strainer wash glutinous rice and transfer in a saucepan. Mix glutinous rice, coconut milk, water, sugar, salt and red sago “tapioca pearls” if using one.
Heat the pan over a low heat until it simmer. Mix continuously until the glutinous rice absorbs all the liquid mixture. Fire off, and let it cool before wrapping in a wilted banana leaf.
To prepare the banana leaves, run the banana leaf over a stove top flame on low, one at a time just enough to wilt the leaves.
Cut wilted banana leaves into 8×8 inches and fold in angle and roll to form a cone. Fill banana leaf with 3 tablespoons of glutinous rice mixture and press down lightly with the back of your spoon to flatten.
Twist the top of the leaf to seal the mixture, then tie with a string. Continue with the remaining rice mixture until done. In a casserole put the extra leaves at the bottom, then arrange wrapped suman “But-ong” and fill with water just enough to cover it.
Boil over on a low heat for about 1½ hour or until glutinous rice are fully cooked.