Heat oil in a saucepan over medium heat. Add onion, bouillon cubes, curry powder, and oregano. Cook, breaking up bouillon cubes, until onion is soft, about 5 minutes. Add couscous and mix thoroughly.
Add water to the saucepan and bring to a boil. Cover and reduce heat to low. Simmer, stirring frequently, until couscous is soft, 8 to 10 minutes.