This will make just 50 1 cup portions, light on the noodles. If this is a hungry crowd, or self serve, you would increase from 10-50 percent more. 1 cup is not a large serving!

12 pounds chicken, cubed or shredded
2 1/2 pounds onions
These need to be cooked. You can use canned chicken, or simmer chicken and onions in some of the water you are going to use to make the gravy.

3 quarts thick well-seasoned gravy, mixed with 1 quart milk (uses about 4 cups of flour total, 2 cups butter or chicken fat)
2 tablespoons crushed not powdered dried green herbs, or to taste
1 tablespoon salt, 1/2 tablespoon pepper
This is made like any thick white sauce, better by far if you use real chicken stock or broth, not water.

2 1/2 pounds noodles, cooked just done and drained

You put the gravy/sauce into the roaster, bring to a simmer, add the cooked noodles and the cooked chicken and onion, stir well.
Heat to a simmer, using about 300-325 on the roaster. Then when everything is added, heat for an additional 35-40 minutes covered at 325, until temp in the middle is 165 degrees.

Turn roaster to 180 to hold.

Topping
2 cups crispy something (for a roaster, french fried onions sprinkled on shortly before serving are a good choice, since nothing gets crisp in a roaster)
mixed with 1-2 cups shredded cheddar cheese or Parmesan cheese
Put on about 10 minutes before serving.

These appliances basically are something like a slow cooker with a metal pan instead of crockery, which can be turned up to normal oven heats. You preheat for 20 minutes just like a regular oven. You cook with the lid on, as each time you remove it, the heat drops and you add to the cooking time. They can be used as a dry oven (they do NOT dry out or crisp up food like a regular oven) or a gigantic cooking pot.

However, the Nesco roaster has a classic recipe for chicken rice soup on their website:
www.nesco.com/recipes/?category%5B%5D=700&submit=recipe&uid=046c56c4c93f

You can substitute 6 ounces of noodles for the rice.