Lightly spray a 6-quart slow cooker with non-stick cooking oil
In large bowl, mix together cream of chicken soup and sour cream. Then add tomatoes, 1 cup cheese, cooked sausage, salt, pepper, and potatoes. Gently stir ingredients together.
Cover and cook on Low heat for 5-6 hours, or High heat setting 3 to 4 hours. After you reach halfway cooking time, pick up insert and turn 180 degrees. This will ensure even cooking time on all sides. We want a nice golden brown color around the whole edge.
Once almost done, add remaining cheese on top. Cover and cook until cheese has melted, about 15-20 minutes.