Start by bringing a medium saucepan of water to a rolling boil over high heat. Add in the sago pearls and cook for about 15 minutes, stirring occasionally. You'll know they're ready when they turn translucent and slightly chewy. Once cooked, remove the saucepan from heat, cover it, and let the pearls sit for an additional 15 minutes to finish cooking.

After the sago pearls have finished cooking, drain them in a colander and rinse under cold water to stop the cooking process. Transfer the pearls to a bowl of cold water to keep them cool and separate until ready to use.

While the sago is cooling, peel and dice your ripe mangoes. In a blender, combine the diced mango with the evaporated milk. Blend until smooth and creamy.

In a large mixing bowl, combine the drained sago pearls, mango puree, and any diced mango pieces. If using optional toppings like coconut jelly or mango jelly, stir those in as well. Add the condensed milk and coconut milk, stirring until all ingredients are well combined.

Cover the bowl with plastic wrap and chill the mixture in the refrigerator for at least 1 hour. Serve chilled over ice if in a hurry.