Cajun Chicken, Shrimp, and Sausage Pasta

butter

lbs medium-size fresh shrimp, peeled and deviened

tbp olive oil

to 2 lbs chicken boneless, skinless, dark or light meat, cut into 1″ cubes

fettuccine

lbs Andouille sausage, chopped

butter or margarine

medium onion, chopped

small green bell pepper, chopped

celery ribs, chopped

garlic cloves, minced

red pepper flakes

salt-free Cajun seasoning

all-purpose flour

chicken broth

heavy cream

pasteurized prepared cheese product, cubed (a.k.a. Velveeta)

chopped green onions

grated Parmesan cheese

chopped fresh parsley