In a large saucepan, put all the ingredients in the saucepan and bring to a boil over moderately high heat. Adjust the heat as necessary to maintain a gentle simmer over low heat until the rice is tender and the liquid is absorbed, about 30 minutes.
Remove from the heat and let steam for 10 minutes, then discard the thyme stems, allspice berries and Scotch bonnet. Using a fork, fluff the rice and nyemba and season with salt. Serve hot.