The most obvious would be tostones....or twice fried and smashed plantains. These are always yummy. Another that I made once is from Food Network: Damaris Phillips "Enchalasagna" but I did make a bunch of changes and decreased the size of the casserole. It gives you an idea anyway and the plantains gave it a nice sweet contrast to the spice of the dish. It was like having a sweet potato in the casserole. You do need to make sure they are ripe plantains.