Place meaty beef bones in a shallow baking pan large enough to hold them in a single layer

Sprinkle with 1/3 of the onion and 1/4 of the carrots

Bake, uncovered, in a 450° F oven for about 25 minutes or until meat and bones are well browned

Transfer beef bones and vegetables to 12-quart kettle

Add remaining ingredients

Bring to a boil over moderately high heat; cover, reduce heat, and simmer for 4 to 6 hours

Strain stock to remove bones and vegetables

Add salt to taste

Cover and refrigerate stock for several hours or overnight

Lift off and discard fat from surface

Leftover stock can be refrigerated for up to 5 days or frozen.