Whiting and watercress burgers | Gourmet Traveller

Ingredients

• 8 whiting fillets
• 150 gm plain flour (1 cup)
• 2 eggs, lightly beaten
• 3 cups fresh breadcrumbs
• For deep-frying: vegetable oil
• 4 soft long rolls, halved
• To serve: butter, softened
• 1 bunch watercress, leaves picked
• Gribiche sauce
• 3 hard-boiled eggs, separated
• 1 egg yolk
• 2 tsp Dijon mustard
• 1 tbsp white wine vinegar
• 400 ml vegetable oil
• 7 cornichons, finely chopped
• 2 tbsp salted baby capers, rinsed
• 2 tbsp each of finely chopped parsley, chervil and tarragon