Recipe: Demi-glace Sauce

Making a Spanish sauce:

1 Place 4.4 lb (2 kg) of broken veal bones on a baking sheet, add 2 onions cut in half (for color), then roast in the oven until deeply browned, then transfer everything to a large pot of at least 10.5 qt (10 liters).

2 Deglaze the pan drippings with water and pour into your pot, cover with cold water (10.5 qt (10 liters)), add 10.5 oz (300g) of carrot mirepoix, thyme, bay leaf, 7 oz (200g) of tomatoes cut into large chunks and 10.5 oz (300g) of button mushrooms cut the same way (previously these were just trimmings), 7 oz (200g) of tomato paste, salt lightly and add 10 crushed peppercorns.

3 Cook for 4 hours at very low simmer while constantly monitoring, remembering to skim impurities with a skimmer and use a small ladle to remove excess fat.

4 Strain this stock through a chinois (about 6.25 qt (6 liters)), it should be translucent

5 Prepare your brown roux:

In your cleaned pot, melt 10.5 oz (300 g) of butter and 0.4 cup (10cl) of oil then add 14 oz (400g) of flour, stir constantly until your roux is dark brown, remove from heat and let cool.

6 Then when your roux is cold, add your boiling veal stock while stirring, thus you have just made a SPANISH sauce.

7 Return to heat and let reduce slowly for another 3 hours until only 1.5 to 2.1 qt (2 liters) of sauce remain, strain it and thus you will obtain this DEMI-GLACE sauce.