The first thing you need to do is make the filling for your pastelles, since it should be cool enough before you fill it. Take a large sauce pan and brown minced meat in it over medium-high heat (no oil needed), stirring occasionally and breaking the meat lumps as it cooks.
While your meat is being cooked, chop the onion, garlic, scallions and both the peppers. Coarsely chop capers and olives as well.
Once the meat is fully cooked, add the chopped vegetables to it and cook them on low heat for 3 to 4 minutes or until soft.
Stir in chopped olives and capers and season the filling with salt, black pepper, Worcester sauce and ketchup. If you are using raisins, add them as well at this stage and cook for another couple of minutes before removing from the heat and allowing to cool.
As the filling cools, make the dough for the outer layer. Combine cornmeal with salt and butter by hand or in a food processor. Add enough water knead or process more to make a soft dough, resembling a pizza dough.
Divide the dough into 12 equal parts, rolling each part into a small ball. Cover the balls with a plastic wrap or a wet kitchen towel to keep them from drying out.
Take one ball, place it on a greased banana leaf and press it until you get a fairly large circle, around 8 inch diameter.
Spoon two tablespoons full of the filling onto the centre of the dough and fold it, using the sides of the leaf, until you get a small package.
Tie it with a clean string and repeat the procedure for the remaining balls.
Place these packages in a pot of water and boil for 15 to 20 minutes.
Drain the water and remove from the leaf. Your pastelles are ready to be served.