Kettle gravy is made from the liquid in which pot roasts and stew have been simmered. Remember, the less liquid you use, the richer the flavor will be.
I like to add a tablespoon of sherry to chicken gravies and brandy to beef gravies. A little white worcestershire sauce for chicken (now called marinade for chicken from Lea and Perrins) and regular worcestershire sauce for beef adds some flavor too, as do seasonings in the broth from the stew or roast. I like carrot liquid in beef gravies for carmelized richness.
For each cup of medium gravy:
1 cup meat or chicken broth
¼ cup cold water
2 tablespoons flour or 1 1/2 tablespoons cornstarch*
Remove meat to platter. Keep warm. Skim excess fat from the broth. Pour off the broth and measure the amount needed and return to the kettle. Shake the flour together in a covered jar, or whisk it together in a measuring cup. Remember to always put the water in first and the flour on top for a smooth mixture.
Whisk the flour and water slowly into the hot, seasoned broth. Bring to a boil. Cook 1 minute until thickened.
*Cornstarch makes a clearer, more transparent gravy.