In Omaha, there's a local chain of restaurants that's known for its potato casseroles. There are at least a dozen of them, with different cheese, vegetables, and meats (or lack thereof), different sauces, different spices. It's kind of a magic recipe because you can take whatever you think might be good in a casserole and throw it together, and it'll come out more or less all right. I give the ingredients I like in the example, but you can easily replace them with just about anything, except for the potatoes and the process.
2 or 2.5 pounds potatoes
1 pound of cooked, diced chicken
1 small, diced tomato
1/2 pound sliced mushrooms
somewhere up to 1 pound of mozzarella cheese
Ranch dressing to taste
Brown potatoes in a skillet. If you have sprinkly spices, add them here.
Grease a skillet with Pam or other substance. Layer in browned potatoes with the ingredients as above. Put some ranch dressing (or other sauce) on halfway through and then again when you get to the top. Sprinkle the cheese on last. Do not scrimp with the cheese.
Bake in 350 degree oven until cheese melts, 20-30 minutes. Yum.
If you're in Omaha, go to the Garden Cafe, the Summer Kitchen Cafe, or the Farmhouse to try these firsthand. I don't know if you can get them anywhere else.