One of the most versatile of the "mother" sauces. Not sure why it fell out of fashion. Take the time and give it a try, you'll love it! I usually serve this over chicken, hence the chicken stock or veggies that have been lightly grilled.
Warm stock in a heavy-based saucepan over medium heat.
Melt butter in another pan. Stir in flour and cook about 3 minutes or so until bubbly. Gradually ass warmed stock, whisking constantly. Cook, uncovered, at a slow simmer for about 50 minutes to one hour, stirring occasionally, until reduced by one-third.
Skim any foam that may have arisen to the top during cooking. Strain through cheesecloth or a fine sieve. Keep hot in a top double boiler until ready to use. Adjust seasoning to taste.
Serve over broiled chicken or lightly cooked vegetables.