Beef bone broth (stovetop, with a pressure-cooker variation)

Optionally clean the marrow out of the bones, which can give the broth an off, metallic taste.

Arrange the bones on racks set in rimmed baking sheets, drizzle with a little oil and roast at 400F for 45 minutes to an hour, until deeply browned and much of the fat is rendered.

Rinse the leek thoroughly between every layer and trim the ends so it fits the pot.

Put the aromatic vegetables, halved head of garlic, black peppercorns, bay leaves and as many bones as fit comfortably into a big, narrow stock pot.

Cover with water and add two tablespoons of apple cider vinegar.

Bring to a bare simmer; during the first hour, skim off the scum, which is harmless denatured protein but makes the broth cloudy.

Simmer for 24 to 48 hours.

Variation, pressure cooker: the same ingredients plus five or six chicken feet with the claws trimmed, for collagen and gelatin; fill to max capacity, add a little apple cider vinegar, cook at high pressure 60 minutes, or up to four hours.

Ideally let the pressure release naturally; a quick release makes the broth cloudier.

Fish out the solids, strain through cheesecloth or at least a fine mesh strainer, portion, chill rapidly in an ice bath and refrigerate.

For the stovetop broth, skim off the thick layer of fat.

Test a small sample by refrigerating it for one hour; it should gel completely.

For a clean broth, optionally filter through cheesecloth or a coffee filter; serve on its own with a little salt.