Heat olive oil over medium heat. Add onion, green pepper and chili flakes. Cook until onions are soft and translucent. Remove from heat and set aside.
In a small pot heat vegetable oil over low heat. Add annato seeds and cook until oil is a reddish-yellow color, about 10 minutes. Remove from the heat, cool and strain.
In a medium bowl combine water, masarepa and salt. Mix until the dough is soft and pliable. Add 2 to 3 tablespoon of annato oil for additional color. Add olives, capers and sautéed vegetables to the corn meal dough. Mix thoroughly to evenly distribute vegetables and flavors.
Bring a large pot of water to a boil. Take one plantain leaf, about 8-10 inches long, and coat with annato oil. Place 1/4 of the dough in a rectangular shape on the edge.
Fold the plantain leaf over the dough, then fold down the sides. Repeat with remaining leaves and dough.
Using bakers twine tie the bollos closed, tying them twice on each side. Once the water is boiling, drop wrapped bollos in the water and cover pot. Boil for 10 minutes. Remove from water and allow to cool slightly.
Serve with hot sauce, a little cheese or sprinkled with paprika.