Preheat oven to 350 degrees.

In a medium pot, boil the plantains with 1 teaspoon of salt, until tender. Remove plantains from the pot and using a potato masher, mash the sweet plantains until they are made pure. Add the butter and combine well. Set aside.

Season the meat with the onion, pepper, garlic, oregano, salt and pepper.

In a medium pan, heat the oil over medium-hot heat. Add the meat and let cook until brown. Add the tomato sauce, olives and water. Let simmer until all the liquid had evaporated.

To Assemble

Lightly butter a 7x11 inch baking pan or 4 mini casserole dishes like the ones pictured. Add a layer of mashed plantains to the bottom of the pan. Then, add a second layer with all the picadillo, cooked ground beef. Sprinkle half of the mozzarella and mild cheddar cheese. Spread another layer of plantains and top with the rest of the cheese.

Place in the oven, uncovered, for about 15-20 minutes or until the cheese has completely melted.

Serve warm.