To make the remoulade sauce, place all ingredients in a blender and process until smooth. Cover and refrigerate until use.
Combine all ingredients for the blackening spice blend and reserve.
Prepare an outdoor grill for direct grilling over a hot fire. Preheat a cast iron griddle or large skillet in the hot zone.
Place the cold tuna, cold shrimp and olive oil in a food processor. Process until the texture is such that the mixture can be formed into patties but is still chunky. Form into 4 equal patties and cover both sides with blackening spice blend.
Add the safflower oil to the hot griddle. Use caution, as you may easily be past the flash point temperature of the oil. (If the oil does ignite, you may proceed with cooking – we are blackening after all -- just be careful not to burn yourself. As always when grilling, make sure you are not wearing loose-fitting clothing.) Quickly add the patties. Cook, flipping once, until done. These patties need to be fully cooked because of the shrimp mixed in.
Spread a little remoulade onto each sliced baguette. Cut each patty in half and add to the baguettes along with some cabbage and tomato slices. Drizzle a little more remoulade over the cabage. Enjoy!