Beef Stock - cooking recipe

Ingredients

2 lbs beef bones (large, cracked)
1 (4 ounce) can tomato paste
1 tablespoon oil (olive, veg, canola)
1 large onion, quartered with skin
2 stalks celery, long with tops cut into 1-inch pieces
2 large carrots, in 1-inch pieces
1 bouquet garni (1 bay leave,1 tsp thyme,6 peppercorns, 2 cloves, 2 tsp parsley in cheeesecloth)
3 quarts cold water

Preparation

Preheat the oven to 375\u00b0F Rub tomato-paste generously over the beef bones.
Roast the bones in the oven for 30 min until browned.
In a large stockpot over medium heat, add oil and saute onions, celery and carrot for 5 minute
Add roasted bones and remaining ingredients and bring to a boil.
Skim off any foam, that rises.
Reduce heat and simmer gently uncovered for 2-3 hours.
Add a few cups of water if necessary.
Let reduce 1/4 of the stock, so 3/4 of the starting liquid are left at this stage.
Strain through a sieve and cheesecloth or damp dishtowel and return to a smaller pot, cool. (Stock should be almost clear).
Reduce another 1/4 of the stock, so that only 1/2 of the starting liquid are left by now.
Chill overnight in fridge.
Remove top layer of solidified fat completely.
Remove gelled stock carefully into new pot, leave any remaining residue on the bottom of the old pot behind.
If the stock is not clear, but needs to be for you recipe, bring to a simmer and add 1 egg white.
Stir constantly and skim the solidifying egg white off the top; it should have cleared the stock.
Use according to suggestions in your recipe.