Source: The Neapolitan Recipe Collection: Cuoco Napoletano. See below for a translation.
pinch of saffron
1/2 cup water
Note on quantities: I took a beaker to be approx. 200 ml. Most historical beakers I've seen in museums were actually larger than that but it looked like a reasonable quantity vs. the other ingredients.
Rub the meat with salt and lay it in a baking dish. Cover it with the fruit and liquids. The liquids shouldn't cover the meat completely, otherwise you'll just get boiled meat. Put it in the oven set at 180 deg Celsius. When it's about half-cooked (after about 20-25 minutes) flip it over and add the spices and the sugar. Keep it in the oven until it's cooked to your taste.
Got no verjuice? No problem!
The original recipe is from this translation:
"Get veal or another meat with the bone, cut it into the pieces as small as a fist, and put them into a baking dish with a little water, a beaker of wine and another of good verjuice; if your master likes, add in a few slices of onion or, should he not like onions, use parsley, the root that is along with raisins, dried prunes, and salt; cover the meat by no more than a finger of water, and set it in the oven; when it looks half done, add a few cloves, a good lot of cinnamon, pepper and a good lot of saffron let it taste of pepper; when it is half cooked, turn it over; then take it out onto a plate with the spices and sugar on top, or else leave it in the baking dish. You can do the same with fish that is, grey mullet or ells cut into pieces four fingers in width, washed well and put into a baking dish with a little oil. Note that you can make these things sweet or tart according to our master's taste."