In a big pot of salted boiling water, prepare the pasta al dente as per the package instructions. After the pasta has finished cooking, drain it and put it back in the pot. Set aside.
Combine the shrimp with a little cajun seasoning in a small mixing bowl. Stir until the shrimp are well coated.
Over medium-high heat, preheat a large skillet. When the pan is hot, pour in half the olive oil before adding the shrimp. Sauté the shrimp until cooked for a few minutes on each side. Take it out of the pan, then leave it aside.
Then, fill the skillet with the remaining 1/2 cup of olive oil. Add Sausage slices to the pan and cooked for a few minutes until browned on each side. Add the onion, peppers, and garlic to the skillet after that. Once the peppers are soft and the onion is transparent, cook for another five minutes or so. From the skillet, take out the sausage, peppers, and onions, and put them in a dish that can withstand heat.
Now prepare the sauce. Add the chicken broth, cajun spice, paprika, lemon juice, and fresh thyme to the skillet. Mix by stirring. Heat the sauce to a boil, then simmer it. Simmer the sauce. Once the sauce has simmered, combine 1 tablespoon of arrowroot starch with a little water to produce a slurry. Stir the slurry into the sauce to thicken it.
Pour the sauce over the pasta in a large pot, then add the sausage, shrimp, and vegetables. Heat the pasta over low heat, and stir everything until mixed well.
Last, add a little shredded cheese and some sliced green onion to the pasta to complete it. Serve with more green slices, and delight in!