1. Preheat the oven to 350°F.
2. In a saucepan, melt the butter and sauté the onions. Add the bisque and cream; mix and heat for 2 minutes.
3. Add the lobster meat and shrimp. Simmer for 10 minutes over very low heat.
4. In a pot of boiling salted water, cook the pasta al dente. Drain and place on a clean towel. Let cool for a few minutes.
5. Using a slotted spoon, remove the shrimp and lobster meat from the sauce to fill the shells with the seafood mixture, very generously.
6. Place the shells in a buttered gratin dish. Spread the remaining sauce in the dish.
7. Bake for 10 minutes.
8. Remove from the oven. Sprinkle with chopped chives and serve with asparagus.