In a mortar, crush peppercorn, garlic, salt and oregano. Blend in olive oil and vinegar. Add seasoning to the beef and mix.Brown seasoning beef in a skillet over high heat reduce heat to low. Stir in tomato sauce and simmer, cover, for 30 minutes.Peel bananas and plantain and cut in half. Grate banana and plantains using the greater disk of a food processor or handheld shredder, mix in a bowl with the achiote.Spread some of the banana-plantain mix in the palm of your hand (keep palms wet while doing this. With your fingers make a small nest in the center of the mix in your palm, and stuff with about a spoonful of the beef filling. Cover the filling with more of the plantain mix and shape into a cylinder or croquette. Repeat until filling and bananas are all used up.Deep fry in very hot oil (375°) until golden brown (about 5 minutes each). Remove and drain absorbent paper towels.