Peel the bananas and cut them in half. Toss with 3 tablespoons of sugar and mix well to coat. Cut the sweet potato into cubes. Soak the tapioca pearls or sweet potato pearls in water until they expand. Place the bananas in a pot and sauté briefly, then add enough water to just cover the bananas.

When the bananas come to a boil, skim off any foam. Add the sweet potato and cook until tender. Add the remaining sugar to taste. Stir in the soaked tapioca pearls or sweet potato pearls, stirring constantly so they don't stick to the bottom. Pour in the entire can of coconut milk and mix well.

Once the coconut milk is fully combined and the mixture comes to a boil, turn off the heat. Ladle into bowls and sprinkle with roasted peanuts.