Makes about 2 quarts
4 # chicken bones
vegetable oil, as needed
1 large onion, chopped
1 leek, washed and chopped
4 sprigs parsley
1 sprig thyme
1 clove garlic, smashed
1 tsp black peppercorns
kosher salt, to taste
Place a large roasting pan in the oven and preheat to 475°F.
Remove the hot pan from the oven, add vegetable oil to lightly cover the bottom of the pan, and then add chicken bones in a single layer across the pan. Quickly return pan to the oven. Roast, rotating and turning bones about every fifteen minutes, until all bones are deeply browned, about 1 hour.
Remove the bones from the roasting pan and place in a large stock pot. Add water to cover the bottom of the roasting pan, place the roasting pan over low-medium heat, and bring to a simmer, using a wooden spoon to scrape up all the browned bits stuck to the bottom of the pan. Remove from the heat and pour this liquid into the stock pot. Cover the bones with 2 1/2 quarts water, place over medium heat and bring to a simmer. Lower the heat and keep at a bare simmer for about 4-6 hours (more time will give you more flavor). Add boiling water as necessary throughout cooking, to keep the bones submerged.
While the chicken bones are simmering, brown the onions and leeks: Heat a sauté pan over medium heat, then add the chopped onions, leeks and about 1 Tbl vegetable oil. Cook, stirring occasionally, until vegetables are well browned. Remove from heat and set aside until needed.
After the bones have simmered for the 4-6 hours, add the browned vegetables, parsley sprigs, thyme, garlic & peppercorns. Season with a good big pinch or two of salt. Simmer 30 minutes. Remove from heat and pour through a fine sieve. Discard the solids. Taste the stock and season with more salt, if needed. Reserve the stock until needed.