A pie by any other name....
The translation of the word küchen is "cake" and would for the modern cook seem to not correlate with the instructions as given in the recipe. The definition of cake appears to have changed over the centuries (a fate shared by a number of culinary terms) and when we look at the origin of the word, then a different understanding of the instructions can be inferred. The following information is the word origin and history according to Dictionary.com:
early 13c., from O.N. kaka "cake," from W.Gmc. *kokon- (cf. M.Du. koke , Du. koek , O.H.G. huohho , Ger. Kuchen ), from PIE base *gag-, *gog- "something round, lump of something." Not related to L. coquere "to cook," as formerly supposed. Replaced its O.E. cognate, coecel. Originally (until early 15c.) "a flat, round loaf of bread." Let them eat cake is from Rousseau's "Confessions," in reference to an incident c.1740, when it was already proverbial, long before Marie Antoinette. The "cake" in question was not a confection, but a poor man's food.
"What man, I trow ye raue, Wolde ye bothe eate your cake and haue your cake?" ["The Proverbs & Epigrams of John Heywood," 1562]
With this understanding of the origins of the word "cake", then I believe my interpretation as a mince meat pie as a "poor man's food" is viable.
Source: This minced meat pie recipe was found in Ein Büch von Güter Speise, 14th century collection of German recipes.
Original Recipe: (transcribe by Hans Hajek)
Diz heizzent heidenisse küchen. Man sol nemen einen teyc. und sol (den) dünne breiten. und nim ein gesoten fleish. und spec gehacket. und epfele. und pfeffer. und eyer dar in. und backe daz. und gibes hin und versirtez niht.
Translation: (by Alia Atlas)
These are called heathen cakes. One should take a dough and should spread it thin and take a boiled meat and chopped fatty bacon and apples and pepper and eggs therein and bake that and give out and do not damage.
Combine stew meat, onion, celery, carrotin stock pot with 1 Tbsp salt and herbs and enough water to cover. Bring to a simmer and cook until meat if fork tender. Remove meat from stock, and shred. Cook bacon until crisp. Remove bacon and let drain on paper towel. Cook diced apple in bacon fat until tender, about 10 minutes. Remove apples and drain on paper towel. Combine shredded beef, apples, bacon, salt, pepper and eggs. Turn into pre-baked pie crusts. Bake at 400F for 10-12 minutes, until egg is set. Each pie will serve 6-8 people.
I originally tried this with a lean ground beef cooked in the bacon fat, but thought the texture of shredded beef cooked to make a stock would yield a more pleasing dish.
Atlas, Alia. "Ein Buch Von Guter Spise." Directory | CS-People by Full Name. Web. 28 Apr. 2011. <http://www.medievalcookery.com/etexts/buch.html#recipe5a>.
Adamson, Melitta Weiss. Daz Bůch [i.e. Buoch] Von Gůter [i.e. Guoter] Spise = The Book of Good Food : a Study, Edition and English Translation of the Oldest German Cookbook. Krems: Medium Aevum Quotidianum, 2000. Print.
Hajek, Hans. "Buch Von Guter Speise (um 1350)." JLU-Homepage. Web. 28 Apr. 2011. http://www.uni-giessen.de/gloning/tx/bvgs.htm.
Dictionary.com. "Cake | Define Cake at Dictionary.com." Dictionary.com | Free Online Dictionary for English Definitions. Web. 28 Apr. 2011. <http://dictionary.reference.com/browse/cake>.