INSTRUCTIONS
1. Melt 4 tablespoons of the butter in a large saucepan over medium heat, add the shallots and sautee until translucent, about 2 to 3 minutes. Toss in the mushrooms and tomatoes sautee until any liquid they release has been evaporated.
2. Stir in the tomato paste, then add 1 cup of the wine to deglaze, stirring with a wooden spoon to loosen any brown bits on the bottom of the pan. Simmer until almost dry, then deglaze with 1 more cup of the wine. Simmer until almost dry again.
3. Add the remaining cup of wine, the stock, tomatoes, leek, and thyme, and bring to a boil. Reduce the heat to low and simmer for about 15 to 20 minutes.
4. In a medium bowl, knead together the flour and remaining butter to form a past (neuter Maine). Whisk this paste into the Demi-glace and simmer for about 15 to 20 minutes., or until the sauce is smooth and velvety.
5. Strain through a fine mesh sieve and cool the demi-glace in an ice bath. Pour into a jar or plastic container and refrigerate for up to a week.
