Sauté onion, celery, and bell pepper in butter until vegetables are transparent; add salt, black pepper, cayenne pepper, and chicken broth and simmer for 20 minutes.

Chop bread slices in food processor or blender and add to vegetable mixture; gently fold in crabmeat and shrimp and remove from heat.

Cool slightly and gradually add eggs, stirring until eggs are absorbed; add green onion tops and parsley.

Stuff mixture into cleaned crab shells or ramekins; sprinkle with bread crumbs and dot with butter.

Bake at 350ºF for 20 minutes or until brown and crusty on top.