Put sliced mangoes into the blender. Turn on the blender until the mangoes are crushed.
Add the condensed milk, crema-asada, and all-purpose cream. Turn on the blender until the ingredients are well-blended.
Transfer the mixture into a big container.
Add the sago, diced gulaman, and diced mangoes. Mix well.
Cover and refrigerate for 1 to 2 hours.
Serve in glasses. Top with diced mangoes if desired.
Enjoy your mango sago gulaman dessert!