In a medium saucepan, pour in the canned coconut milk and add enough water to fill the can halfway. Stir in the sweetened condensed milk, mixing well. Heat over medium heat, bringing it to a gentle boil; watch for bubbles forming. Once boiling, remove from heat and let the mixture cool completely.

Fill a large pot with water and bring it to a rapid boil. Add in the sago pearls, stirring gently to prevent sticking, and let them simmer for about 10 minutes. After this time, turn off the heat and cover the pot, allowing the sago to sit undisturbed for another 10 minutes. Drain and rinse under cold water.

In a large mixing bowl, combine the diced mango and coconut jelly. Gently stir in the cooked sago pearls and then fold in the cooled coconut milk mixture.

Cover the bowl with plastic wrap or a lid and refrigerate for at least 3 hours before serving.

Scoop the Mango Sago with Coconut Jelly into bowls or glasses before serving.