There are so many versions of Cajun Seafood Pasta, and this one isn't from any particular recipe site but is a conglomeration of many different recipes that utilized the best parts of the top rated recipes. It's one is best served with a loaf of hearty bread, to capture every bit of the delicious sauce.
2Toss garlic cloves with oil in small baking dish. Cover with foil and bake until garlic is tender, about 40 minutes. Remove from oven; cool. Peel garlic and mash with fork. Set aside.
3Melt butter in heavy large pot over high heat. Add sausage and mushrooms and cook until brown, about 7 minutes. Stir in Cajun seasoning. Add clams, mussels, clam juice, tomatoes and reserved roasted garlic. Cover pot and cook until clams and mussels open, about 6 minutes (discard any clams and mussels that do not open). Using tongs, transfer clams and mussels to large bowl. Add shrimp and halibut to cooking liquid. Cover and cook until opaque in center, about 3 minutes. Return clams and mussels to pot. Season with salt and pepper.
4Meanwhile, cook pasta in large pot of boiling salted water until tender but still firm to bite, stirring occasionally. Drain well. Transfer pasta to large bowl.
5Spoon seafood sauce over pasta. Garnish with green onions and serve.