Recipe: Demi-glace Sauce

Making a Spanish sauce:

1- Place 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 liters.

2- Deglaze the pan drippings with water and pour into your pot, cover with cold water (10 liters), add 300g of carrot mirepoix, thyme, bay leaf, 200g of tomatoes cut into large chunks and 300g of button mushrooms cut the same way (previously these were just trimmings), 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 liters), it should be translucent

5- Prepare your brown roux:
In your cleaned pot, melt 300 g of butter and 10cl of oil then add 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 liters of sauce remain, strain it and thus you will obtain this DEMI-GLACE sauce.
This sauce is an extract and should only be added sparingly to give body to other sauces (sauces such as charcutière, piquante, Bercy, Madeira, Port, Bercy, Bordelaise, Périgueux, Périgourdine, Genevoise, Robert etc).
And to finish anyway my little trick: when your Demi-Glace is strained and cold, pour it into ice cube trays and into the freezer