Warm the oil in a dutch oven or large stock pot over medium high heat. Season the chuck roast with kosher salt and freshly ground black pepper and brown in the pot on all sides then transfer to a plate or platter. Add the bones and brown in batches on all sides. Add the chuck roast to the pot with the browned bones, carrot, celery, onion, garlic halves and parsnip (if using. Add 4 quarts cold water, covering the beef and veggies by at least 1-2 inches. Add a handful of the parsley (with leaves and stems intact), thyme sprigs, peppercorns, bay leaves, beef bouillon and kosher salt.

Bring to a boil, then reduce to a simmer and skim the stock with a fine mesh strainer every 30 minutes or so. Cook partly covered for 2 hours up to 8 hours or until the stock is rich and brown and tastes well flavored. Add more salt to taste if necessary.

Turn off the heat and allow the broth to cool or if using immediately, place a large colander over a Pyrex 4 cup glass measuring cup and slowly drain the broth from the rest of the aromatics so the colander catches any veggies or bones that may fall from the pot. Then, use a fine-mesh strainer to strain the stock into your next recipe's soup stock pot. Or, if storing to use later, strain into 1 quart wide-mouth glass canning jars and cool before adding a tight fitting lid. Refrigerate for up to 5 days or freeze in gallon bags for up to 6 months.