Preheat the oven to 350F and grease a 9X13 glass baking dish.
Bring a large pot of salted water to a boil.
Meanwhile, combine the chicken, cream of mushroom soup, Ro*Tel tomatoes, 2 cups of the shredded cheese, and the seasonings in a very large bowl.
Once the water is brought to a boil, cook the spaghetti until al dente, about 9 minutes.
Drain the spaghetti in a colander.
Add the cooked and drained spaghetti to the soup and chicken mixture. Toss well to combine.
Pour the mixture into the prepared baking dish, and spread it out evenly.
Sprinkle the remaining ¾ cup of shredded cheese on top of the casserole, cover and bake for 20-30 minutes, or until bubbly and the cheese is melted.
Serve and enjoy!