Preheat the oven to 400°F (205℃). Line a baking sheet with foil and spray it with cooking oil.
Using a sharp knife, cut both ends off the plantains to make it easier to peel. Slit a shallow line down the long seam of the plantain, cutting only as deep as the peel. Remove the peel by pulling it back.
Place the plantains on the baking sheet and lightly spray them. Bake for about 25 minutes, turn, and bake on the other side for another 15 minutes or more until golden brown and tender. How long will depend on the plantains.
Remove baked plantains from the oven, cool for a couple of minutes, make a horizontal slit in the plantains, and stuff with the cheese slices.
Place back in the oven for a couple of minutes until the cheese melts. Remove and serve immediately.
Notes
Your favorite plant-based cheese will work fine, a sauce, grated, or sliced.
Ripe plantains work best, green ones take longer to cook and don't have as much flavor, and overripe plantains are too soft.