Preheat the oven to 325°F (160°C). In a medium bowl, pour the chicken stock and sprinkle the gelatin evenly across the surface, allowing each portion to absorb before adding the next. Set aside to bloom.

In a large Dutch oven, heat the vegetable oil over medium-high heat until shimmering. Season the beef generously with 3 teaspoons of salt and the black pepper. Place the beef into the pot and sear, turning occasionally, until richly browned on two sides, about 10 minutes. Transfer the beef to a rimmed baking sheet.

Lower the heat to medium and add the split carrots, halved onion, and garlic to the Dutch oven. Cook, turning occasionally, until lightly caramelized, about 4 minutes. If using, pour in the cognac or brandy and allow it to boil for around 2 minutes, cooking off the alcohol.

Scrape the chicken stock and gelatin mixture into the pot. Add the red wine, fish sauce, soy sauce, and bouquet garni, stirring to combine, and bring the mixture to a simmer over medium-high heat. Meanwhile, cut the seared beef into 2-inch chunks and toss them in a large bowl with the flour until evenly coated.

Add the floured beef chunks and any accumulated juices back into the Dutch oven. Bring the pot to a simmer again, then partially cover and transfer it to the oven. Let it cook until the beef is starting to become tender, about 2 hours.

Meanwhile, in a large nonstick skillet over medium-high heat, render the bacon lardons, stirring occasionally, until the fat has been released and the lardons are golden and crisp, about 4 to 6 minutes. Remove with a slotted spoon and set aside.

Using the same skillet, sauté the mushrooms over medium-high heat, stirring occasionally, until they release their moisture and turn golden brown, about 10 minutes. If the pan becomes dry, add a splash of oil. Stir in the diced carrots and pearl onions and cook until lightly browned, about 5 minutes more.

Remove the Dutch oven from the oven. Discard the large pieces of carrot, onion, and the bouquet garni. Skim off any visible fat from the surface using a ladle. Stir the reserved lardons, sautéed mushrooms, carrots, and pearl onions into the stew. Return the uncovered pot to the oven and cook for an additional hour, or until the beef is fork-tender, the pearl onions are soft but hold their shape, and the sauce has thickened to a rich consistency (nappe).

When ready to serve, skim any remaining fat from the surface. Adjust seasoning with additional salt and pepper as needed. Let the stew cool slightly before serving, garnished with minced parsley for a burst of freshness. If making in advance, allow the stew to cool completely, refrigerate, and remove the solid fat layer before reheating gently on the stovetop or in a low oven.