In a large skillet, bring the stock to a boil with a generous pinch of salt. Remove from the heat, add the saffron and let steep for 5 minutes. Return the chicken stock just to a boil. Add the orzo and cook over moderate heat, stirring occasionally, until the orzo is al dente and the stock has been absorbed, about 8 minutes. Remove from the heat, stir in the oil, season with salt and pepper and serve.