In a medium saucepan, heat the oil. Add the raisins, garlic, cinnamon, cumin, and coriander. Cook, stirring, for 1 minute. Add the couscous to the saucepan, along with the 2 cups of boiling water and the salt. Stir once with a fork, cover tightly, and remove from the heat. Let stand, covered, for 5 minutes. Stir with a fork before serving to fluff the couscous and combine the other ingredients. (This recipe can be made up to a day ahead and reheated over very low heat or in a microwave oven.)