Peel and boil in water ( just covering the pieces of Plantain) for about a half an hour, or till a fork can go right through them. Remove Plantains and put them in a deep bowl. Mash. They will be lumpy at first. Add water from the pot you cooked them in. I used almost all the water in the pot, and keep mashing. Add Salt & Pepper, add 3 Tbsp. butter or margarine. If they do get cool, warm them in the microwave oven for about 2 minutes on High.
For Left over Mashed Plantains, simply make a large meatball with them, flatten them down and be sure to pack in the sides. Fry in about 3 Tbsp Olive Oil till golden, flip over, and fry the other side. Instant Plantain Fritters.
It doesn't get better than this! I have them for breakfast with juice and fruit.