The next day drain the meat, saving the marinade, and pat it dry. Lightly coat pieces with flour. Heat the fat or oil in a 12-inch saute pan over medium high. Slowly brown the meat pieces in 2 batches (so pieces don't touch) until golden on all sides. Watch the heat, taking care not to burn the brown glaze forming on the bottom of the pan. Sprinkle meat with salt and pepper as it cooks. Remove from the pan.
Stir in the onions and herbs from the marinade. Cook until onions are soft. Stir in 1/4 of the marinade and reduce to nothing. Do the same with a 1/2 cup of stock.
Put meat back in the pan, turning to coat with the onions. Add the rest of the marinade and stock. Bring to a very gentle simmer, partially cover, and cook about 45 minutes, or until meat is tender (if breasts cook faster, remove them from the pan once they're done).
After 30 minutes, stir in drained prunes to the pan. Once meat is tender, remove it to a heated platter. Taste sauce for rich, full flavor. If it's weak-kneed, boil down for a few minutes. Either way, stir in the jelly and vinegar, boil 2 minutes and pour over the meat. Serve hot with steamed red-skinned potatoes or Yellow Finns.
Andrea Reusing is the creator of the restaurant Lantern in Chapel Hill, N.C., and author of the book Cooking in the Moment: A Year of Seasonal Recipes. In this installment of The Key 3, she shares with Lynne Rossetto Kasper the techniques behind three of her favorite recipes: Turnip Soup, Overnight Braised Short Ribs and Tomato Salad.