To prepare the fish:

Line a plate with paper towels and set by the cooktop.  

In a large bowl, stir together the mustard, egg white, and hot Sauce. Add the fish and toss to coat well. Cover and marinate in the refrigerator for 1 hour.

In a shallow dish, combine the cornmeal and flour and season with salt and pepper. Pour the oil into a heavy-bottomed saucepan, deep fryer, or Dutch oven, filling it no more than one-third full.

Heat the oil over medium heat until it reaches 350°F.

Remove the fish from the marinade and season with salt and pepper. Dredge the fish in the cornmeal mixture to coat both sides and shake off the excess. Carefully add the fish to the oil, a few pieces at a time. Cook until golden brown and crispy, about 2 minutes. Remove with a slotted spoon to the prepared plate. Taste and adjust for seasoning with salt and pepper. Serve with the remoulade.

To prepare the remoulade:

Thoroughly combine the mayonnaise, mustard, lemon juice, celery, onions, chives, garlic, and hot sauce; taste and add salt and pepper. Refrigerate for at least one hour before serving, will keep, refrigerated, in an airtight container for up to three days; serve chilled. Makes about 1 ½ cups.