Safran
In France, saffron cultivation probably started during the 13th century. Crocus sativus was likely introduced from Spain and from the Middle-East by pilgrims, merchants, and Knights. Its first uses are documented in the south-west of the Kingdom around 1250. It is indeed unlikely that Kings and Religious didn't try growing Crocus sativus by that time: Saffron was rare, expensive, and demanded, and Crocus sativus could be farmed under France's latitudes. By the 14th century, the wide use of saffron for spicing and coloring food is documented in recipe books such as the "Viandier de Taillevent", written by the King's cook. And by the 15th century, local saffron farming is attested with taxes levied by the religious power, which reveal how important saffron crops must have been. For instance, in 1478, the saffron tax levied by the Bishop of Albi reached 1/12th of saffron production.