2 tablespoons butter
2 tablespoons all-purpose flour
1/2 teaspoon salt
1/4 teaspoon white pepper
1 teaspoon chicken bouillon granules
2 tablespoons finely chopped onion
1 1/2 cups half-and-half cream
1/2 pound medium shrimp - peeled and deveined
1/2 pound pre-cooked crab meat
1/2 cup white wine