Sauce: Combine fish stock, milk and cream and set aside. Make a roux of butter and flour. When cooked, stir in sun-dried tomato paste and whisk in liquids; bring to a boil and simmer for 5 minutes. Season well to taste with salt and cayenne.
Seafood Filling: Saute lobster and crab in butter to warm; add tomatoes and wine and reduce. Stir in basil and chives. Season well with salt and pepper.To assemble: Cut lasagna into strips large enough to fit into 9 x 13 inch pan. Parboil lasagna strips, a few at a time for a minute in boiling water. Chill in ice water; dry on cloth towels. Preheat oven to 400 degrees. Butter pan generously. Layer some lasagna noodles, barely overlapping the edges. Spread some sauce over top and dot sauce with seafood filling; layer until pan is filled. Finish with a layer of sauce, sprinkle with breadcrumbs and dot with butter. Bake for 20 to 25 minutes; cool for 10 minutes before serving.