For the stewed tomatoes: Combine the sugar, breadcrumbs, tomatoes and 2 cups water in a large bowl. Crush the tomatoes using a potato masher until broken into small pieces, and then pour into a large cast-iron pan. Simmer over low heat until reduced into a thick sauce, stirring often (or every time you pass the pan), about 3 hours.
Meanwhile, put the fish fillets in a baking dish and cover with lemon juice. Let marinate in the refrigerator 20 minutes.
For the coleslaw: Toss together the carrots and cabbage in a bowl to combine. Mix the mayonnaise, sugar, vinegar, salt and pepper in another bowl, adjusting the seasoning as needed. Pour the dressing over the carrots and cabbage and stir to combine. Refrigerate at least 20 minutes.
Preheat a charcoal grill over medium-high heat.
Grill the fish, what was once the skin side down, 5 minutes. Meanwhile, combine the butter and crab seasoning in a bowl and brush over the top of the fish while it's grilling. The thickness of the fillets will determine when the fish needs to be flipped. If thicker than 3/4 inch, you will need to flip the fish after 5 minutes (or when the fish is willing to let you do so). When the fillet has good grill marks, transfer to a plate and serve with desired amount of the stewed tomatoes and coleslaw alongside. Garnish each plate with a piece of kale and lemon, if using.
This recipe was provided by a chef, restaurant or culinary professional and makes a large quantity. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.