Citation:
[1] D. Banham, “The earliest English culinary recipes: Dietary advice in Old English medical texts,” Journal of Medieval History, vol. 49, no. 5, pp. 711–724, Aug. 2023. doi:10.1080/03044181.2023.2250943
The task of creating a plausible 12th century Norman/English feast is not an easy one. The earliest (during the medieval period) set of culinary recipes (not medical) that I am aware of in this region is "The Forme of Curry" from 1390. Since the target of this feast is post conquest England in the beginning the 12th cen this cookbook is approximately 250 years after the target era.
There are four (known to myself) medical texts that give recipes that are to treat specific ailments that range in publication date from the 10th to the 12th century. Although these recipes can not taken as everyday foods it can be used as a shopping list of sorts. All food items in the recipes were, at the least, known at the time of the writing. It is hard to say from these sources if these items were common, thought of as normal food items or specialty medical items but these categorizations may be able to be determined from other sources.
For more information specifically on what I did to make bread and pottage see Anglo Saxon Food A&S Entry
The four sources are as follows:
Pre-Conquest:
Bald’s Leechbook (BLB I and BLB II), estimated date 800-950AD
Leechbook III (LBIII) and the 800-1000AD
Lacnunga (Lac)
Post Conquest:
Salsamenta Pictavensium (SP), 12th cen
The Following Table is a list of the mentioned ingredients in [1] for the different medieval texts with the number of times the ingredient is called for in each text. NT = Not Translated
The Following is from [1] and contains all the recipes and their translations from BLB I, BLB II, BLB III and Lac