How to Make It
Preheat oven to 275°F. Heat oil in a large Dutch oven over medium-high. Sprinkle short ribs evenly on all sides with 1 tablespoon plus 1 teaspoon salt and pepper. Working in 2 batches, sear short ribs, turning occasionally, until well-browned on all sides, about 15 minutes per batch. Carefully pour off all but 2 tablespoons drippings from pot between batches. Transfer browned short ribs to a plate while continuing to brown remaining short ribs.
Pour off excess fat from Dutch oven, leaving about 2 tablespoons. Add onion, carrots, celery, garlic, and remaining 1 teaspoon salt. Reduce heat to medium, and cook, stirring occasionally and scraping bottom of pan to loosen browned bits, until softened, 7 to 10 minutes. Add vinegar, and cook, stirring often, until liquid has almost completely evaporated, 2 to 3 minutes. Add hard cider, broth, brown sugar, onion powder, and bay leaves. Carefully return browned short ribs and any accumulated juices to pan, nestling them, meaty side down, into liquid. Return to a simmer over medium-high, and cover.
Transfer to preheated oven, and braise until meat is tender and easily pierced with a paring knife, 2 hours to 2 hours and 30 minutes. Remove from oven, and let meat rest 20 minutes in juices.
Transfer short ribs to a serving platter, and cover with aluminum foil to keep warm. Skim off and discard fat. Return Dutch oven to stovetop, and bring juices to a simmer over medium-high. Reduce heat to medium-low; gently simmer until braising liquid is slightly reduced and concentrated in flavor to taste, 10 to 15 minutes. Season with salt and pepper to taste. Spoon desired amount of sauce over ribs, and sprinkle with parsley and lemon zest. Serve with remaining sauce.
To make this recipe ahead of time, prepare through step 3, and let cool completely. Cover and refrigerate up to 2 days. To reheat, proceed with step 4, but leave the short ribs in the pan to reheat with the sauce.