For garnishing, have quenelles half-spherical shape, decorated with truffles and filled with a cream forcemeat, then poached in a slow oven; as soon as they are firm to the touch, unmold and set them in a vegetable dish with a little consomme and some rice cooked in white broth, some very small fresh green peas and rounds of red carrots, blanched and cooked in broth; serve separately a soup tureen of chicken consomme.
This is a garnish formula rather than a soup recipe: Ranhofer assumes you already have clear chicken consommé and are only building what goes into the cup. The whole thing hinges on poaching the quenelles gently enough that they set without puffing or weeping.
Charles Ranhofer, chef at Delmonico's in New York, published The Epicurean in 1894 as an exhaustive catalogue of the French repertoire as it was practised in an American luxury restaurant, and its soup chapter runs to dozens of consommés that differ only in garnish. That is the logic of classical garnish nomenclature: the broth is the same clear chicken consommé, and the name records what floats in it. Titles like à l'Impératrice belong to the nineteenth-century habit of dedicating dishes to royalty, and the epithet is generally traced to Eugénie, empress consort of Napoleon III, whose name attaches to a long list of Second Empire preparations; the attribution is conventional rather than documented in any single kitchen record. The decorated mousseline quenelle, unmolded whole and set in the cup with rice and turned vegetables, was a display of a brigade's precision as much as of flavour.