Cook the spaghetti to al dente in a saucepan according to the package directions; drain.
Step 4
Return the cooked spaghetti to the saucepan and stir in the chicken, spinach, cream of chicken soup, mayonnaise, sour cream, celery, onion, green pepper, pimientos, and lemon-pepper seasoning.
Step 5
Transfer the pasta mixture to the prepared baking dish.
Step 6
Top the casserole with the Monterey Jack cheese, bread crumbs, and parmesan cheese.
Step 7
Bake, uncovered, until heated through and the cheese is melted, for about 25-30 minutes.