Make the ube-stuffed bilo-bilo: take 1 teaspoon galapong and form into a ball. Roll out into a small disc and put a dollop of ube jam in the middle. Fold over the galapong and roll back into a ball, making sure the jam is sealed in. repeat to make a total of 20 balls. Set aside.

Place water in a large pot and bring to a gentle simmer. Add 13/4 cups coconut milk and continue to simmer.

Add sweet potatoes and gabi; Simmer gently for about 6 to 8 minutes.

Pour in remaining coconut milk, sugar, and bilo-bilo; stir. Simmer until the bilo-bilo rises gently to the top, about 5 minutes.

Add saging na saba and langka; cook for 2 minutes.

Turn off heat and add cooked sago. Stir gently, being careful not to overmix. Transfer to a serving bowl and serve hot.