This is an excellent sauce, and it is employed as one part of the essential base for many elegant sauces that accompany beef dishes.
4 ozBrown Roux
6 cBrown Stock
1⁄2 lbTomato Puree
Heat the roux and add the stock. Simmer for an hour or more, skimming the scum that rises to the top. Add the tomatoes and mirepoix and continues stirring and skimming for another hour. If it gets too thick, add more Brown Stock.
When it has lightened/clarified considerably, strain into a wide tureen and stir constantly while it cools.