Boil water in a pot and cook ramen noodles for 2 minutes until al dente; drain and set aside.
Melt butter in a large skillet or Dutch oven over medium-high heat.
Add andouille sausage and sear until browned, approximately 3-4 minutes.
Add shrimp and 0.5 tablespoons of Cajun seasoning; sauté until shrimp are opaque, then remove shrimp and sausage from the skillet and set aside.
In the same skillet, sauté onions and bell peppers until softened, about 5 minutes.
Stir in minced garlic and the remaining Cajun seasoning; cook for 60 seconds until fragrant.
Pour in chicken stock and Worcestershire sauce, scraping the bottom of the pan to deglaze.
Bring to a simmer, then stir in heavy cream; reduce heat to medium and simmer for 5 minutes until slightly thickened.
Return sausage and shrimp to the skillet and stir to combine.
Add the cooked ramen noodles to the sauce, tossing thoroughly to coat.
Divide into bowls and garnish with sliced green onions.