Cutting the guava: Wash the guavas and halve. Scoop out the seeds using a teaspoon. Cut the guavas into wedges and set the wedges aside.
Boiling seeds: Boil the seeds and the cinnamon sticks over medium heat in 4 cups of water for 10 minutes. Add water if it becomes necessary to maintain the same level of liquids.Remove from the heat and sieve, discard the solids.
Cooking guavas: Pour the liquid back into a pot and add sugar, plantain, and sweet potato.Boil over medium heat until all the ingredients are cooked throughout. Add water as it becomes necessary to maintain the same level of liquid.Add the guava wedges and boil for another five minutes, let enough of the liquid evaporate to obtain a light syrup.
Serving: Remove from the heat and cool to room temperature. If you want to add milk, mix it in now.Chill before serving.
Notes
For this recipe you will need fresh guava, but if can't find it, then we suggest you buy them canned.While the vast majority of people who have actually tried this dish do not add milk to it, I have found a couple that have. Feel free to try whichever you think you'd like.