Heat butter in a large pot over medium heat. Stir in green onions, and cook briefly. Add parsley and crawfish, and simmer about 7 minutes, stirring frequently. Stir in flour to coat crawfish.Advertisement
In a small bowl, mix together egg yolks and evaporated milk. Stir into crawfish, and reduce heat to medium-low. Gradually add cheese cubes, stirring continuously until the cheese has melted. Season with salt, pepper, and hot pepper sauce. Remove from heat, and bring to room temperature before serving.