Sauce too Runny
You could make a roux in another pan. Melt grease (butter) in the pan and add an equal amount of flour, cook it slowly, and stir it a lot. When it starts to color, you can add it into your sauce and cook it a bit. Really, you should bring it to a boil before turning it down. It may only take 1 or 2 tablespoons to work. You'll get the feel of it.
What you probably have in the pan is a mix of what you added, meat juices, and meat fat. You need to pour into a narrow container like a glass measuring cup, and let it sit a few minutes so the fat starts to rise to the top. Depending on the amount of fat, and the taste of the rest of the juices (how salt?), you have several choices.
You could skim off the fat, and serve the juices, not as a gravy but as a dip.
You could thicken the juices with a corn starch slurry, or you could make a roux with the fat and flour. If you don't know how to thicken a sauce (including making a simple white sauce), I suggest reading up on the topic. Any general purpose cookbook will do.