Homemade Filet-O-Fish Burger (BAKED!)

Bahan-bahan (4 porsi)

• 2 cups panko breadcrumbs ((Note 1))
• 400 - 500 g / 0.8 - 1 lb white fish fillets (, flat / thin (I used Ling, Note 2))
• 4 soft buns (, brioche recommended (Note 3))
• 4 slices processed cheese ((Note 4))
• Oil spray ((I use olive oil))
• 1 egg
• 1 tbsp mayonnaise
• 1 tbsp dijon mustard ((or other mustard))
• 1 tbsp flour
• 1/2 tsp salt
• Black pepper
• 1 cup / 220g mayonnaise
• 1 tbsp dill pickle / gherkin/ cornichon (, very finely chopped)
• 1 tsp fresh parsley (, chopped*)
• 1 tsp capers (, drained and finely chopped*)
• 1.5 tbsp lemon juice (, fresh (or cider vinegar))
• 1 tsp white sugar
• 1/4 tsp salt