To make the sauce:

1. Combine all of the ingredients in a bowl and whisk well to combine. Refrigerate until chilled.

To prepare the crab cakes:

1. Melt 1 tablespoon of butter in a heavy skillet over medium heat. Saute the onion, bell pepper, and garlic until the pepper is limp, approximately 3 minutes. Add the cream, mustard, 1 egg, parsley, cayenne pepper and 1/2 cup bread crumbs, to taste, and mix well. Gently fold in the crabmeat.
2. Form the mixture into 8 patties, about 1/2-inch thick. In a mixing bowl, combine the remaining 1/2 cup of bread crumbs with the Parmesan. Pat this topping onto both sides of the patties. Refrigerate until firm, about 2 hours.
3. Using a skillet, combine the oil and remaining 2 tablespoons of butter. Saute the crab cakes in the hot oil-butter mixture for approximately 3 minutes on each side or until golden brown.