Preheat the oven to 160°C and line a baking tray with non-stick baking paper.
In a small bowl, combine the cornflour, parsley, salt and pepper and mix. Coat the cod fillets well in the cornflour mixture.
Add the egg and breadcrumbs to two clean bowls. Dip the first fillet in the egg then in the breadcrumbs coating on all sides. Place onto the baking tray and repeat with the second fillet.
Spray the top of the cod fillets with low-calorie cooking spray and place the tray into the oven for 12 minutes. Turn the fillets over and respray with low-calorie cooking spray, cook for a further 15 minutes. The breadcrumbs should be golden brown, and the cod should be flakey and cooked through.
In a small bowl, combine the mayonnaise, tartare sauce and lemon juice mix until smooth.
Spread the tartare sauce mixture onto the top and bottom of the bread rolls. Once cooked, add a cod fillet to each bun, top with rocket and place the top half of the bun on top. Serve with an accompaniment of choice.