Not "fancy" fleet cuisine. Ingredients are as follows.
Flour x1 +
Butter x1 +
Horse Mackerel x1
It appears as a 17th Century period 3 World Clock limited recipe in Florence's Chamber of Commerce, from Cook NPC for 10 Cooking contribution points. I helped someone unlock
Secret of Sharing Info using this relatively cheap and easy recipe, though better options no doubt exist.
I also could find no evidence of the recipe existing elsewhere using GVDB, but it is possible I have overlooked something.