While flour is a great way thicken sauce (it acts by binding liquid with starch molecules) you can't just simply stir it in without ending up with a clumpy mess. Here are a few options to avoid the ...
If you're making gravy from scratch, you can thicken it with a roux, a slurry, or Wondra flour. While a roux is typically made at the beginning of the gravy-making process, a slurry or Wondra flour ...