Step 1

In a 5-quart slow cooker, combine the cream of chicken soup, chicken broth, onion, garlic powder, salt and pepper. Then add the chicken and cook on low until tender, about 4 to 5 hours.

Step 2

Transfer the chicken from the slow-cooker to a cutting board. Allow it to sit for a minute or two to cool slightly, then use two forks to shred the chicken. (Just be sure not to wait too long—shredding is easiest when the chicken is still warm.) When you're done, return chicken to the slow cooker.

Step 3

Cook pasta according to the package's directions to al dente. Be sure to salt your water—this gives noodles some flavor right from the start. Use 1-1/2 tablespoons of kosher salt for every pound of pasta or for every gallon of water in the pot. Drain pasta when it's done cooking.

Step 4

Stir pasta, cheese and sour cream into the slow cooker, and mix well with shredded chicken. Cover and cook on low until the cheese is melted, about 15 to 20 minutes. Garnish with green onions and additional cheese if you like.