In a food processor, combine ginger, scallion, scotch bonnet pepper, thyme, allspice, nutmeg, soy sauce, and rum, process until smooth.
Duck legs:
With a knife poke small holes in the skin of the duck legs.
In a pan coat the flesh side of the duck legs with the jerk paste.
Apply salt and brown sugar to the whole leg and skin. Place the pan of legs into the fridge for twenty-four hours.
Wipe excess mixture from the legs.
In a pot heat the duck fat. To the melted duck fat add the whole scotch bonnet pepper, garlic, allspice berries, ginger, whole scallion, thyme.
Immerse the duck legs into the fat mixture and cook for three hours at 225 F (105 C), or until the meat turns brown and soft when prodded with a knife.
Remove the pan from the heat and let cool to room temperature. Transfer to a container to refrigerate or serve immediately.
To serve immediately remove to duck legs carefully from the warm oil and drain off the access liquid. In a cast iron frying pan on medium high heat place the duck leg skin side down to sear the skin.
Plantain:
In a pan heat strained duck fat to med high or 375 F (190 C).
Place the plantain in the heated oil and fry until brown on all sides and slightly crisped.
