For the remoulade: Combine the mayonnaise, chopped onion, chopped red pepper, capers, chopped parsley, mustard, hot sauce, salt, and pepper, to taste in a small mixing bowl. Reserve the mixture as a condiment.
For the crabcakes: Heat half of the olive oil in a medium saute pan over medium heat. Add the onions, celery, and peppers. Season the mixture with salt and cayenne. Saute for 5 minutes. Add the garlic and continue to saute for 2 minutes. Remove the pan from the heat and cool for 5 minutes.
In a medium mixing bowl, combine the crabmeat, mayonnaise, Creole mustard, and hot sauce. Fold the cooled sauteed vegetables, mayonnaise and bread crumbs into the crab mixture. Mix gently, but thoroughly.
Reheat the same pan of the vegetables with butter and remaining olive oil. Portion the filling into 1/3 cup balls. Form the balls into patties, about 1-inch thick. Gently place the patties in the hot pan and saute just until brown on both sides.
Serve 1 cake with a salad of greens, tomatoes and dressed with salt and truffle oil. Serve with the reserved remoulade sauce.