Step 4: Build the Onion Gravy - Pour the chicken broth into the skillet and begin scraping the bottom gently with a
wooden spoon or spatula. All those browned bits from the chicken will loosen and melt into the broth, which is a big part of what gives this simple gravy its savory depth. In a small bowl, whisk the cornstarch with the cold water until there are no visible lumps. While stirring the broth, slowly pour in the cornstarch mixture. Keep stirring for 1 to 2 minutes as the sauce begins to thicken. At this point it should lightly coat your spoon but still look loose enough to simmer around the chicken.