Cook the plantains with the skin on until they split. Drain, remove the skins, and mash the plantains. Mix with the egg and breadcrumbs, then set aside.

In another pot with water, add the carrots and salt. Cook for a few minutes, then remove the carrots and add the potatoes to the same water. Cook the pasta for a few more minutes, then drain.

In a large bowl, combine the pasta, tuna, carrots, potatoes, mayonnaise, and sour cream. Mix gently so you don't mash the ingredients.

For the patties, with clean hands, take a ball of the plantain mixture and shape it into a patty. Add the filling, close it, coat with flour, and fry in hot oil. Drain on paper towels, then serve.

For the mandarin water, squeeze the mandarins well, remove the seeds, sweeten with sugar to taste, and serve.