In a small bowl, combine mayonnaise, lemon juice, diced pickles, Dijon mustard, and sugar. Mix until smooth and set aside.

In a skillet over medium heat, add oil or butter. Toast the inner sides of the potato buns until golden, about 2-3 minutes.

Dice 15 shrimp into approximately 6 pieces each and chop 5 shrimp into larger chunks. Combine for texture.

In a bowl, combine prepared shrimp, salt, beaten egg, parsley flakes, diced onion, potato starch, and breadcrumbs. Mix gently.

Shape the shrimp mixture into two round patties, about ¾ inch thick, and roll in extra breadcrumbs.

Heat vegetable oil in a non-stick pan. Fry the patties for 3-4 minutes on each side or until golden brown and crisp.

Place each crispy fried shrimp patty on toasted buns. Spread tartar sauce and add chosen fresh toppings before serving.