1. Preheat oven to broil
2. In a large bowl, add the whitefish, greek yogurt, celery, scallions, jalapeno and celery seed. Fold together.
3. Place 6 pieces of bread onto a baking sheet, divide the whitefish salad onto the 6 pieces of bread. top with cheese and place under broiler until the cheese is melted and bubbly.
4. Serve whitefish melt with celery root remoulade on the side.
5. For remoulade: to a medium bowl, add celery root, sweet gherkins, mayonnaise, salt, lemon zest and juice, mustard and sherry vinegar, whisk combine.
6. Tips: Use a food processor fitted with a greater attachment to grate the celery root.