Food Network and Chow.com have simple and easy to follow recipes for brown mushroom gravy. Food Network's recipe pairs it with a Salisbury steak, while Chow.com's pairs it with meatloaf.
To make Food Network's recipe, add 1 tablespoon butter and 1/4 cup cognac to a pan. Sauté 8-ounces sliced fresh mushrooms for seven to eight minutes. Add 2 cups beef broth and whisk in 1.2-ounces brown gravy mix until smooth. Stir in 3/4 can mushroom soup. Let simmer, and serve with Salisbury steaks.
To make Chow.com's recipe, heat 3 tablespoons butter until foaming. Add 6-ounces sliced and trimmed cremini mushrooms, 1 tablespoon finely chopped shallots, salt and pepper. Cook until the mushrooms are slightly browned and soft. Reduce heat to medium and sprinkle on 1/4 cup flour. Stir to coat the mushrooms, and cook until the flour is lightly toasted. Add 1/4 cup dry Marsala wine and stir with a wooden spoon. Scrape up browned bits from the bottom. Cook until the wine is completely reduced. Slowly stir in 2 cups beef broth or stock and whisk until smooth. Bring to a boil and cook, until the gravy has thickened. Remove the pan from the heat and stir in 1/4 cup heavy cream.