Need a Dark Mushroom Sauce recipe

A local steak house served a rich dark mushroom sauce for steaks and baked potatoes. It was delicious!!All the mushroom sauce recipes I've seen are light in color. Any idea how to make this?

[cape chef]

Jesse, It's all about the stock.
This is a basic way to prepare the sauce.
Buy some dried porcini mushrooms and reconstitute in Sherry and a little warm water. Strain the mushrooms through cheesecloth and reserve the liquid. Rinse the shrooms again and set both aside. Now in a heavy based sauce pan saute a couple rough cut shallots,some garlic cloves,parsly stems,a couple day leaves and sprigs of fresh thyme and a few peppercorns. Do this on medium high heat,When you start to get some nice caralization going add 1 small chopped tomato and stir season with some kosher salt and reduce to a sec. Then deglaze the pan with 2 cups red wine and reduce by half,then add the liqiud you saved from the shrooms and reduce that by half, at this stage you should have a fairly nice color working. Jesse if you have veal stock this is when you add it 4 or 5 cups,bring to a boil, season with s & p and simmer down by 1/3. If you do not have stock add some beef boullion,But do not add any salt until you taste the broth,they tend to be salty. Make a little roux (be sure to cook it out) and add this alittle at a time until you get the consistency you want. (coats the back of a spoon)Then strain this through a fine china cap or a colander lined with cheese cloth into another pot. Fine dice a shallot and mince a little fresh thyme, saute together in a saute pan add the shrooms S&P cook till hot add 1/2 cup red wine reduce to sec and add to your sauce, Adjust the seasoning and poof you should be on you way.
Happy cooking!!
cc

Thank you! I was hoping for this. This is better than Mushrooms, gravy and Beef base. Thanks.