Cook the pasta in a large pot of boiling salted water until al dente. Drain and coat lightly with oil. Set aside.
In a large non-stick sauté pan or Dutch oven over high heat, sear the shrimp and scallops for about 1 minute in 30 ml (2 tablespoons) oil. Season with salt and pepper.
Set aside on a plate.
In the same pan over medium heat, soften the shallot and garlic in the remaining oil. Season with salt and pepper. Sprinkle with the flour and paprika and continue cooking for 1 minute. Slowly whisk in the clam juice and milk. Bring to a boil, stirring constantly, and simmer gently for 1 minute. Add the mussels. Cover and simmer for
3 minutes. Add the pasta, shrimp, scallops and fish and toss well. Cover and continue cooking until the fish and seafood are cooked, 3 to 5 minutes. Adjust the seasoning. Discard any mussels that did not open during cooking.