Soak bananas in hot water for 10 minutes. Peel bananas and finely grate into a bowl. Add 1/2 cup of the achiote oil and 3 teaspoons of the salt; mix well. Set aside. In a food processor, or with a mortar and pestle, process or grind garlic, oregano, the remaining 2 teaspoons salt, and the pepper. In saucepan, heat 3 tablespoons of the remaining achiote oil. Add pork and brown with the garlic mixture. Add onion, green onions, and parsley; cook for a few minutes. Stir in tomato sauce, red peppers, and olives; cover and simmer for one hour. Preheat electric oven to 450°F. Oil a 13 x 9 x 2-inch baking pan with the remaining 1 tablespoon of achiote oil. Combine banana and pork mixtures; put in prepared pan. Cover with ti leaves. Seal pan with heavy foil. Place pan into larger pan filled with water to a depth of 1-inch. Bake for 1 1/2 to 2 hours. Makes 12 servings.