4 cups (950ml) homemade or store-bought low-sodium chicken stock
4 packets powdered unflavored gelatin (1 ounce; 30g)
2 tablespoons (30ml) vegetable oil
3 pounds (1.25kg) whole boneless beef chuck roast, cut into 3 steaks
Kosher salt and freshly ground black pepper
4 medium carrots (10 ounces; 275g), 2 split lengthwise, 2 cut into bite-size pieces
2 small stalks celery (3 ounces; 85g)
1 large yellow onion, thinly sliced (10 ounces; 275g)
2 red bell peppers, thinly sliced (8 ounces; 225g)
4 cloves garlic, thinly sliced
1/2 cup sweet Hungarian paprika (about 2 ounces; 55g)
1 tablespoon (15ml) soy sauce
1 tablespoon (15ml) Asian fish sauce
2 bay leaves
4 sprigs thyme
2 tablespoons flour (about 3/4 ounce; 20g)
1 pound (450g) Yukon Gold potatoes, peeled and cubed
1 to 2 tablespoons (15 to 30ml) apple cider vinegar
Chopped fresh parsley leaves, for serving
Sprinkle gelatin over chicken stock and set aside. Adjust oven rack to lower position and preheat oven to 275°F. In a large Dutch oven, heat oil over medium-high heat until shimmering. Season beef all over with salt and pepper and add to Dutch oven. Cook, turning occasionally, until beef is well browned on 2 sides, about 10 minutes. Transfer beef to a rimmed baking sheet or large plate and set aside.
Add diced carrots to Dutch oven and cook, stirring, until well browned on all sides, about 4 minutes, lowering heat as necessary to prevent scorching. Season to taste with salt and pepper, then transfer to a bowl and set aside. Add split carrot, celery stalks, onion, peppers, and garlic and cook until onion and peppers are softened and lightly browned, about 8 minutes.
Add paprika and cook, stirring, until fragrant, about 30 seconds. Add chicken stock/gelatin mixture, followed by soy sauce, fish sauce, bay leaves, and thyme.
Cut seared steaks into 1 1/2- to 2-inch chunks and transfer to a large bowl. Toss with flour. Add beef and any juices accumulated in the tray or plate to the Dutch oven. Stir to combine and return to a simmer over medium heat. Transfer to oven, cover with lid partially open, and cook until beef is starting to become tender, about 1 1/2 hours. Liquid should remain at a slow, steady simmer throughout. Adjust oven temperature if necessary during cooking.
Remove stew from oven. Using tongs, fish out and discard carrot, celery, thyme, and bay leaves. Add potatoes and reserved sautéed carrots to stew, return to oven, and continue to cook, partially covered, until beef, potatoes, and carrots are tender and broth has thickened, 45 minutes to 1 hour. Using a ladle, skim off any excess fat from the surface of the stew and discard.
Remove stew from oven. If necessary, place over a burner and simmer for up to 15 minutes to reduce to desired consistency. Add 1 to 2 tablespoons vinegar (to taste). Season to taste with salt and pepper if necessary. Serve immediately, sprinkled with parsley. Alternatively, let cool overnight or refrigerate for up to 5 days and reheat to serve.