In a large saucepan, melt butter over a low heat. Stir in flour, salt, white pepper, bouillon granules, and onion. Blend 3/4 cup half-and-half cream into the mixture. Mix in shrimp and crab meat. Turn the temperature to medium heat and continue stirring until the mixture thickens.
Blend the remaining half-and-half cream and wine into the mixture. Serve and enjoy!