Bacon, onions, carrots, celery, potatoes and garlic all go into the oven with the brisket to marinate with it and exchange flavor profiles, enriching the entire dish. Before sitting in the oven with the brisket, the side dishes are browned separately in preparation for inclusion in the master recipe at the end of cooking.
The carrot and bacon both help to impart moisture to the brisket and to keep it from drying out while it cooks. The pork fat in the bacon and the water in the carrot are potent sources of moisture, and they can even be inserted into the brisket so that they are absorbed as it cooks.
Onions help to thicken the wine-based gravy with their juices and to flavor the brisket with their oils and excretions. Celery provides body to the sauce in which the brisket marinates and from which it draws its complex medley of flavors, overtones and undertones both, while garlic further enriches this gravy.
Potatoes help to control salt dispersion inside the gravy. This keeps the flavor savory and prevents the salt content from overwhelming its complex wine-influenced palette. In the end, a good mixture of hearty sides and sides intended solely to enrich flavor and gravy are included in the recipe and cooked to perfection alongside the brisket.