Remove the pot from the heat and stir in the cheese. Add salt and pepper to taste. Toss the shrimp in the Cajun seasoning and set aside. In a large sauté pan over medium heat, heat the olive oil.
Meanwhile, in a medium bowl whisk together broth, soy sauce, oyster sauce, fish sauce, sugar and Cajun spice ... Add butter, shrimp and crawfish tails, if using. Cook just until pink.