Melt eh butter in a sauce pan at approx. 300 degrees F. Add the vegetables and saute until slightly browned. Remove form the heat. In a seperate pan heat the Half & Half being careful no tto boil it. Reduce heat to approx. 150 degrees F. and slowly stir in the flour. When it is blended well, add the seasonings & spices. Add the browned vegetables and the drianed oysters & scallops. Simmer for 15 minutes, stirring frequently. Add the sherry and contimue to simmer until the stew thickens. Add the croutons and serve!