My Casserole Creation: 

11/2 cups leftover macaroni and cheese 

1 cup freshly cooked penne (the dregs from the bottom of the container) 

3/4 cup frozen pieces of cooked chicken, leftover from a roasted chicken a few weeks ago 

4 slices bacon, cooked and cut into chunks – leftover from my kids plates three days ago 

1 cup frozen peas (last of the bag, little freezer burned but still good. That's why there's a sauce) 

2 cups basic white sauce (on the thinish side) 

1 cup shredded cheese (mixture of cheddar and mozzarella) 

bits of herbs from the garden, but I don't know what they were (tarragon, maybe? parsley for sure) 

salt and pepper 

I did this in a crockpot because it was 90* outside and we had to go to baseball. So I dumped the mac and cheese in the crockpot, added in the cooked penne, thawed peas (run them under warm water and shake well), the thawed cooked chicken, crumbled bacon and the white sauce made with cheese. Stirred it all up and put it on low for about 2 hours. Voila! My pantry challenge create a casserole, crockpot style. 

Make your own Casserole: there are measurements here only to give guidance 

2 cups, give or take, carbohydrate of some sort (pasta, rice, potatoes, croutons, waffles, whatever) 

1 cup of protein (meat, chicken, tofu, egg, fish – canned tuna or salmon work well) 

1 cup vegetable (peas, or corn, or mixed frozen vegetables, or whatever is leftover from supper last night) 

2 cups basic white sauce or other binder – canned soup, sour cream, gravy, cheese sauce) 

salt and pepper to taste 

herbs, to taste – basil, parsley, thyme 

Make your basic white sauce – melt 1/4 cup of butter or margarine with 3 Tbsp flour. Cook the flour, stirring constantly, for one minute or so. Pour in a little milk to make a smooth paste, then whisk in about 2 cups of milk, or one cup of broth or bouillon and one cup of half and half. Cook over medium heat until the sauce boils and thickens. Add salt and pepper to taste. If you are adding cheese, add it after removing the pan from the heat and just stir until the cheese melts. 

You can cook your casserole in the oven or in the crockpot, whichever is easier. Even the stovetop works. Basically throw it all together, top it with something if you want to – breadcrumbs, crushed crackers, chips – and bake for about 30 to 45min or heat for about 2hrs.