For green plaintains: Tostones: Peel the bananas and slice diagonally, about 1/4" thick. Heat up palm or coconut oil, and fry until soft. Remove from the pan, and smash it on a board with your fist. Fry them again until brown. Drain and salt to taste. Please note: The right oil is essential for the real taste. I learned to make these in Panama.
You can also cut them up, and add them to a curry instead of potatoes. Like we did in St. Lucia.
If they are yellow with black, you can slice them, and saute' them in butter with a little orange juice. If you want the glaze to carmelize, just keep cooking to let the juice to evaporate and the bananas to brown. Goes well with a scoop of vanilla ice cream or as a side dish.
For meat eaters: Using yellow with black plaintains, peel and slice it diagonally. Cut bacon strips in half and break some toothpicks in half. Wrap the bacon around the plaintain, and secure with the half toothpick. Fry until well browned.
I hope this helps,
Jasmine