Soups: Basic Beef Stock Preheat Oven: 375 degrees
2 1/2 - 3 lbs. Beef bones with some meat left on them
3 medium Onions, chopped coarsely, skins on
2 stalks Celery, chopped coarsely, greens on
3 large Carrots, chopped coarsely
1 large Bay Leaf
12 Peppercorns, whole 
Salt
3 qts. Water
Wash beef bones and pat dry. Place on a deep cookie sheet or shallow baking dish, leave space around each bone. Sprinkle lightly with salt. Place into 375 degree oven and roast for 30-40 minutes until bones are dark golden brown, time will depend on how large your bones are. Place bones in large soup pot. Drain fat from baking dish. Put small amount of water in baking dish, place on stove top, bring to a gentle boil and use wooden spatula to scrape the bits from the bottom of the pan, add this to the soup pot.
Add water and bring to a boil. Skim any foam that may form (roasting the bones eliminates most of this as well as adds flavor to your stock.) Add vegetables, peppercorns, bay leaf and 1 tsp. salt. Bring back to a boil, reduce to simmer. Cover and simmer for 4-6 hours, stirring occasionally, longer is better. Remove from heat and allow to cool slightly. Use slotted spoon to remove bones and large pieces of vegetables. Pour stock through strainer or colander lined with cheesecloth to remove small pieces of vegetables and peppercorns. Discard everything in the strainer.
Refrigerate in large bowl until fat solidifies. Remove fat. Use stock as base for soup or put into tightly sealed containers for storage. Stock can be frozen for up to 1 year. For quick access to small quantities, freeze in an ice cube tray and store in a baggie.
TIPS:
My soup pot lid has a vent hole in it so that my stock concentrates to about 2 1/2 quarts by the time it's finished. If yours doesn't, simmer the last hour with the lid off.