Step 1

Preheat oven to 350°F. Spray a 9 x 13-inch baking dish with cooking spray and set aside.

Step 2

Cook spaghetti in a large pot of salted boiling water according to package instructions for al dente (almost tender, but still with a little bite). Drain and return to the pot.

Step 3

Add chicken, bell pepper, celery, onion, pimentos or Rotel, condensed soup, broth, ½ cup of the cheddar cheese and all of the Velveeta. Toss to combine; season with salt and pepper to taste.

Step 4

Transfer spaghetti mixture to prepared dish. Sprinkle remaining 1 cup of cheddar cheese over top.

Step 5

Bake (uncovered) for 45 minutes, or until the casserole is hot and bubbly and the cheese is melted on top.