As it cooks down it will thicken even more.

In a sauce pan add 1 bag of cranberries, 2 cups of cherries, and one cup of sugar. Stir until sugar has fully coated the fruits. You can use frozen or fresh its fine (stay away from canned as it will add preservatives and sugar that is unnecessary for this recipe). Place the heat on medium. Constantly stir the berries and sugar because sugar will burn if unattended. As the berries began to heat they will pop and burst. This is all apart of the process as it will aid to the thickening of the sauce. Once the sugar has drawn out some liquid turn the heat down to low and let the sauce cook for 6 minutes. Occasionally stirring and checking for desired thickness. Cranberries can be quite bitter so to counter that bitterness you will now add the juices. I measured them out in tbsp. Add them and stir, cook for another 2 minutes then taste. If the sauce is still bitter then add a little more of the juice of your liking. Until the bitter edge of the fruit is gone. Let this cook on the stove for 10 minutes unattended on low heat. Remove from heat and let it rest. Once you come back to the sauce it will be thick and have an intense cranberry flavor. A flavor you have never tasted before, a flavor that is often lost in canned and store bought sauces. 

Now just before you serve first you need to decide if this is the desired texture. If not then what I suggest is using a blender made specifically for chopping or use the pulse setting on your food processor. I didn't like the chunks of berries in the sauce so I blended it with a small food processor. It came out perfect. Let it rest in the refrigerator before serving. Now this sauce can be used as a topping for desserts or you can eat as a side dish for Thanksgiving or Christmas Dinner.