The flavor of this recipe is sweet and sour, similar to modern Chinese Sweet and Sour sauce, with a pronounced taste of fennel. The proportions in the original recipe did not account for additional liquid sauce left over after frying the meat, since all of the sauce cooks away into the meat. It might be an improvement to make a second batch of sauce and reduce it for 5 minutes less than the recipe calls for in order to be able to pour it over the meat as it is being served.
If you do not have Sapa already pre-made you will need to make it before you begin this recipe. To make Sapa see the Sapa recipe instructions.
For a more authentic taste use wine vinegar from Spain, either Sherry or Sweet Moscatel, which have a stronger taste, or Sweet Pedro Ximenez vinegar, which has a milder taste. All of the above mentioned vinegars are made based on recipes closer to what the Romans would have used. A very good brand of Spanish wine vinegars is Los Villares, which can be purchased in Whole Foods Supermarkets throughout the US.