How did 'cordon bleu' come to be applied to cookery?

Solution 1:

From its official website; The name Cordon Bleu ( the association with cookery was due to the feasts given to celebrate the high royal officials):

• has been used for the first time in relation to culinary excellence since the 16th century when King Henry III created one of the most important orders in France, “L’Ordre du Saint-Esprit.” Symbolizing this order was the cross of the Holy Spirit which hung on a blue ribbon or un cordon bleu. Due to the prestigious nature of this Order and the decadent feasts accompanying their ceremonies, the name Le Cordon Bleu became well recognized and celebrated.

• Le Cordon Bleu, as a culinary arts school, was founded in Paris in 1895 by the journalist and publisher of La Cuisinière Cordon Bleu magazine, Marthe Distel. On January 14th, 1896 the first cooking demonstration ever to be held on an electric stove was staged at Le Cordon Bleu in an effort to promote the magazine and launch the Paris cooking school. From this point on, the international reputation of Le Cordon Bleu spread rapidly. Great chefs came to the school to teach students further contributing to the world-renowned reputation of the school. As a result, students from a variety of countries were enrolling in classes as well as notable figures including Julia Child in 1950.