Makes about 1 gallon (can be frozen for later use)

3 oz. vegetable oil
1 lb. mirepoix (one part chopped celery, one part chopped carrots and two parts chopped onions)
2 oz. tomato paste
1 gallon hot beef or veal stock
2 Tbsp. parsley, unchopped
2 Tbsp. thyme, unchopped
3 peppercorns
1 bay leaf
1 clove garlic, crushed
Salt and pepper to taste

For roux*:
2 sticks (1/2  pound) butter
1/2 pound all-purpose flour
* Roux is equal parts butter and flour. It is best to measure  by weight rather than volume.

1. Sweat the mirepoix in vegetable oil in a large pot until the vegetables begin to look translucent, 5 to 10 minutes. Do not let them brown.
2. Whisk in tomato paste and cook for several minutes until a sweet aroma develops.
3. Add stock and bring to a simmer. Add herbs. Simmer for one hour, skimming away any foam that develops on the surface.
4. Strain out all of the vegetables and herbs. Return broth to the pot on medium heat.
5. Melt butter in a skillet. Whisk in flour until a smooth roux forms. Continue whisking constantly over a low to medium heat until the roux has turned the color of peanut butter. Be careful not to burn it.
6. Bring stock to a boil and gradually add roux, whisking constantly, until the sauce has thickened to the point where it will coat the back of a spoon. Salt and pepper to taste.

Use this sauce with: Chicken Marsala

Source: Steve Alls, Kroger