Suprême is a French term very common in haute cuisine, which has a double meaning; the first refers to a delicate white sauce based on reduced cream mixed with chicken broth and cream, and served as an accompaniment to fish, previously cooked in a pan or 'drowned'.
On the other hand, the second meaning refers to a preparation made with chicken breasts or fillets of game or fish (sole or turbot) cooked quickly in a pan, and accompanied by an elaborate sauce, but sometimes also by truffles.
By extension the definition 'suprême' indicates different kinds of highly refined haute cuisine preparations.