SKIMMING (oil from sauce)
This is a technique that requires a little patience. When a cooked dish such as stew, or a pot roast, comes out of the oven, let it sit for about five minutes. In that time the oils in the dish will collect at the surface because they are lighter that the other liquid.
By gently tilting the pot, the oils will further collect in a deeper pool. Carefully place a large spoon under the surface letting in the oil. Discard the oil as you remove it from the pot. When the spoon yields up as much other liquid as the fairly clear oil you are removing, it is sufficient. You could now stir together the whole liquid and serve it.
The book illustrates this at the end of the beef stew preparation process. You can see the contrast of the oil and the other liquid collecting in the spoon.
If you find the meat is fork tender, skim excess fat from the top of the dish before stirring it around, or serving it.