Trim the ends off the plantains and place them in a large saute pan filled with salted boiling water. Cover and boil for 20 minutes.
Then, using a pair of kitchen tongs, carefully remove the plantains to a plate and allow them to cool for about 5 to 10 minutes, or until they can safely be handled with bare hands.
While the plantains are cooling, drain the water from the pan, place it back over medium-low heat and melt the coconut oil. Add the sliced onions and bell peppers and cook, stirring often, until just softened and slightly fragrant, about 2 to 3 minutes.
Delicately peel the plantains; once cooked, that peel is very easy to remove, especially if your plantains have swollen and cracked open in the cooking process. If the peel is still intact, simply run a paring knife along the length of the fruit. Slide your fingers under the peel; it will come right off.
Cut the peeled plantain into 8 to 10 thick slices and throw them in the pan with the onions and bell peppers. Add salt, pepper and chili flakes and stir delicately.
Transfer to a baking dish, pour in 1/2 cup of coconut water, cover with foil and bake in the oven for 20 minutes.
After that time, remove the foil, sprinkle with toasted coconut flakes and return to oven for 10 minutes, or until the top turns beautifully golden.