Make Ahead: The stock can be prepared and refrigerated for up to 3 days ahead or frozen for up to 3 months.

3 pounds beef bones (preferably 2 pounds soup bones, and 1 pound meaty beef shin or short ribs), sawed into 2 to 3-inch pieces
1 medium onion, chopped
1 medium carrot, chopped
1 medium celery rib, with leaves, chopped
6 parsley sprigs
1/2 teaspoon dried thyme
1/4 teaspoon whole black peppercorns
1 dried bay leaf

1. Position a rack in the upper third of the oven and preheat to 450°F. Place the bones in a large roasting pan. Roast, turning occasionally, until deeply browned, 30 to 45 minutes.

2. Meanwhile, in a large pot, heat the oil over medium-high heat. Add the onion, carrot, and celery to the pot and cook, stirring often, until softened, about 6 minutes.

3. Transfer the bones to the pot. Pour off all fat in the pan. Place the pan over two burners at high heat. Add 1 cup of water, scraping up the browned bits in the pan with a wooden spoon. Pour into the pot. Add enough cold water to cover the wings by 2 inches. Bring to a boil, skimming off the foam that rises to the surface. Add the parsley, thyme, peppercorns, and bay leaf. Reduce the heat to very low. Cook at a bare simmer for at least 2 and up to 12 hours, the longer the better. As needed, add more water to the pot to keep the bones covered.

4. Strain the stock through a colander into a large bowl. Let stand for 5 minutes and skim off the clear yellow fat that rises to the surface. Cool the stock completely before refrigerating or freezing. (The stock can be prepared up to 3 days ahead, cooled completely, covered and refrigerated. It can also be frozen in airtight containers for up to 3 months.)