8 pounds venison bones (or 4–5 pounds waterfowl or upland bird carcasses)
3 Tbsp. olive oil
1 large onion, skin on, quartered
3 carrots, roughly chopped
1 parsnip, roughly chopped (optional)
3 stalks celery, roughly chopped
5 garlic cloves, peeled and smashed
3 bay leaves
1 Tbsp. black peppercorns
Kosher salt, to taste
Preheat oven to 400 degrees. Spread the bones or carcasses on a sheet pan and rub with the olive oil. Roast for 1 hour, turning the bones once or twice.
Pile the rest of the ingredients, except the salt, into a large stockpot. Add the roasted bones, and then add cold water to cover the bones by just an inch or so. Bring to a simmer over medium-high heat, being careful not to let it fully boil.
Reduce the heat to low so that it simmers very gently, with just a few bubbles nipping the surface. Occasionally skim off any scum that develops on the surface with a large spoon. Simmer this way, uncovered, for about 6 hours or longer.
Use a slotted spoon or tongs to remove the bones and other large solids, and discard them. Strain the stock through a cheesecloth- or paper-towel-lined sieve into another pot or into storage containers. Discard the filtered solids, and allow the stock to slightly cool. Add salt to taste.
Refrigerate the stock. Once chilled, skim off any fat that has risen to the top. Freeze stock for up to 6 months, or use refrigerated stock within a week. You can also return some of the stock to the pot and reduce it down to a demi-glace, a stock's gelatin-rich essence. Portion into ice trays, freeze, and add a cube to any dish for a boost of flavor.
2–3 lb. heads and bones from white-fleshed fish, rinsed
1 Tbsp. unsalted butter
1 large onion, roughly chopped
2 celery stalks, roughly chopped
1 large leek, white and pale-green parts only, roughly sliced
1⁄2 cup dry white wine
2 bay leaves
Kosher salt, to taste
Heat the butter in a stockpot over medium heat. Add the onion, celery stalks, and leek, and cook, stirring, for about 5 minutes. Add the fish heads, bones, and wine, then reduce the heat to medium-low and cook, covered, for about 8 minutes.
Add the bay leaves and peppercorns, and then add cold water to cover everything by just an inch. Bring to a very gentle simmer, reduce the heat to low, and continue to simmer for about 30 minutes, with just a bubble or two slowly breaking the surface.
Use a slotted spoon or tongs to remove the fish heads and bones and other solids, and discard them. Strain the stock through a cheesecloth- or paper-towel-lined sieve into another pot or into storage containers. Discard the filtered solids, and allow the stock to slightly cool. Add salt to taste.
Use the stock immediately, or refrigerate for future use for up to a week. You may also freeze it for up to 6 months.