Grynd reysons; draw with bastard, clare, osey or othir swete wyn, the best thu may gete. Take datys cut grete, reysons of coraunce, clovis, macys, pynes, & floure of canel, yf thu have hit. Pure hit in a pot, & some of the good wyn therwith. When hit ys boyled ynowghe, take the syrip of the reysons & creme of almondes & past ryall & pynad & gobet ryal & gynger in confite & charde quynsys or chard wardyns, poudyr gynger & poudyr of canell: do al thes togedyr yn a pot. Set hit on the fyre. Stere hit wel. When hit ys at the boylyng, take hit of; loke hit be doucet, and that hit have ynowe of poudrez & somdell of salt.
Dresse hit forth as a flat potage, & yf thu servehit forth hote, colour hit with blossemys of safron. Have fisch braune sodyn tendyr & drawyn thorowgh a streynour, & colour hit with safron that hit be as brycht as lambur. When hit is cold, floresch the sewe therwith in dysches & serve hit forth.
For comparison, from the "Two C15 cookery books":
Cxlij. Vyande Ryalle.--Nyme gode Mylke of Almaundys, & do it in a potte, & sette it ouer ŝe fyre, & styre it tyl it boyle almost; ŝen take flour of Rys & of ŝe selue Mylke, an draw it ŝorwe a straynoure, & so ŝer-with a-lye it tylle it be Chargeaunte, & stere it faste ŝat it crouste not; ŝen take owte of grece, & caste it ŝorw a Skymoure, & colour ŝat Sewe ŝer-with; ŝan take Sugre in confyte, & caste in y-now; sesyn it with Salt & ley ŝre lechys in a dysshe, & caste Aneys in comfyte ŝer-on, & ŝanne serue forth.
Ordinance of Potage does not attempt to suggest how to re-create this dish, saying that it would be very difficult. And I have the nerve to try? Well, why not?
Starting with the syrup of raisins: take raisins, grind them, mix with sweet wine. That's easy enough. I used a sweet cooking sherry in my first test, which may have been OTT, but medieval "sweet" wines were a lot sweeter than ours. For the Feast version, I got a bottle of Muscadet (graded as a 7 by the supermarket).
"Take datys cut grete, reysons of coraunce, clovis, macys, pynes, & floure of canel, yf thu have hit."
Dates, currants, cloves, mace, pinenuts: but what is "floure of canel"? Not "poudyr of canell", that's mentioned separately, later. I can only think it means the flowers of the cinnamon plant. Still, it's "yf thu have hit". And I don't. So we take all these things, put them in a pan, and heat until boiled "enough": which I interpret as being until the dates have started to break down into a mush.
Then we take this mixture and add:
"the syrip of the reysons"
"& creme of almondes": almond cream, a recipe for which is given as OP#103
and looks like almond milk made extra thick by curdling with vinegar.
A warning is given that this is difficult, so I just thickened by reducing.
"& past ryall": a recipe for this is given at OP A6, and looks like a means of whitening sugar. I used caster sugar.
"& pynad": pynonade? A sweet I've done before, involving pears, pine nuts, and almond milk. Since all these ingredients are already present, and I do not have pynonade sitting in the fridge asking to be used, I ignored this.
"& gobet ryal": this is the one OP says we have no recipe for. However, "gobet" normally means a lump of something, and just above, "past ryal" meant sugar. The 2C15 recipe for "Vyande Ryalle" uses "Sugre in confyte" as one of the ingredients. So what I used was those sugar crystals intended for coffee. As long as you add them near the end, they stay solid and add texture to the mix.
"& gynger in confite": ginger in syrup is obtainable, if expensive. I assume this is to be finely chopped.
"& charde quynsys or chard wardyns,": pears. If I could get quinces, I would, but I can't.
"poudyr gynger & poudyr of canell": ginger and cinnamon.
Put all that lot in a pot, and boil.
Then we have to serve it: cold, as a "flat pottage" is suggested. It looks to me like a sauce to be served with the roasts of the first course. But we also get told how to garnish it: and I must admit, this is where I looked at the instructions and decided that either the writer was insane or I was. But I tried it anyway.
"Have fisch braune sodyn tendyr & drawyn thorowgh a streynour, & colour hit with safron that hit be as brycht as lambur." Boiled fish (well, microwaved coley steak). Mashed, and coloured with saffron.
I served this to my testers and refused to tell them what it was until after they'd tasted and commented. They liked it. It sounds completely insane, I know, but fish with that incredibly rich sweet & sour sauce works.
Quantities? Yes. Quite. "Enough", "some", and so on.
On my first trial at home,
I got through about 250g of dried fruit in all, one cooking apple (didn't have any pears to hand),
one chunk of candied ginger, about 2 tablespoons of ground almonds,
and 6fl oz of wine (what was left from another recipe).
About 1 teaspoon of each spice (only 1/2 tsp of cloves).
Enough water to make up the almond milk, and to stop things getting too thick.
Caster sugar has to be "to taste". And a handful of sugar crystals.