Beef bone broth

Optionally clean all 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 400 degrees Fahrenheit for 45 minutes to one hour until deeply brown.

Rinse every layer of the leek thoroughly and chop the ends off.

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

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

Bring to and keep at a bare simmer, skimming off any scum during the first hour of cooking.

Simmer for 24 to 48 hours.

Pressure cooker version: same ingredients plus five or six chicken feet with the claws trimmed off, filled to max capacity with a wee bit of apple cider vinegar; high pressure for 60 minutes, or as many as four hours.

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

Skim the thick fat layer off the chilled stovetop broth.

Test a small sample refrigerated for one hour; it should have completely gelified.

Savoury whipped cream: whisk a cup of heavy cream with a couple tablespoons of fresh chopped dill and a couple generous pinches of kosher salt until homogenous, then whip.

Tortellini en brodo: a pat of butter in the serving bowl, lightly seasoned hot broth, freshly cooked al dente four cheese tortellini; top with nutmeg, parmesan, lemon zest, fried garlic chips and minced chives.

Udon version: broth over udon noodles topped with spicy chili oil, a drizzle of sesame oil and chopped green onions.

Demi-glace: put about two quarts of bone broth in the widest stockpot with two or three tablespoons of tomato paste and one cup of dry red wine, simmer and reduce by as much as 75 percent to a thick syrupy sauce.

Cool the demi-glace, portion into a cupcake tin to set into pucks, wrap or vacuum seal and freeze for up to six months.

Pan sauce: sear steaks and deglaze the pan with one portion of demi-glace and a little red wine.