Add flour and whisk together thoroughly. (make a rue)
Add broth milk whisking to thoroughly combine each time.
Add spices to desired tastes
Bring to a boil. Turn heat down and allow to simmer until desired thickness is achived. You may add flour or milk to thicken or thin as you desire. You may add gravy browning if you like. It is not very popular any more but some still like the darker color it provides.