Cheesy Chicken Spaghetti - With greens

1 green pepper , diced 1 cup celery , diced 1 medium onion , diced 2 tablespoons butter 2 cups cooked chicken, boned (save broth) 1/4 cup pimiento 1/4-1/2 cup[...]

9 ounces uncooked spaghetti cooking spray 1 cup frozen chopped onion 1 tablespoon bottled minced garlic 2 (14 1/2 ounce) cans stewed tomatoes , undrained and[...]