Boil plantains with salt until tender.
Remove plantains from water and mash to a paste. Add butter and continue mashing until smooth.
Preheat oven to 350.F. Grease a baking dish with butter. Spread half of the plantain mixture on the bottom of the pan, cover with a layer of cheese, meat, plantain, and remaining cheese.
Bake until top is golden brown.
Let rest briefly before serving.
Made with 4 plantains and 2 sweet potatoes; Dominican picadillo; and white cheddar. I used the mashed sweet potatoes for the bottom layer (instead of plantain). This is pretty good, but a bit too sweet because of the slightly overly large plantain top layer. The plantains I used were also very, very ripe, which likely contributed.