Thaw K&N's TenderBrest fillet as per instructions on pack.
In a bowl, add mustard paste, black pepper powder, salt, garlic powder, onion powder, vinegar, and oil.
K&N's TenderBrest in this for 30 minutes.
Grill on a preheated pan for 3-4 minutes from each side.
Set the grilled fillets on a platter and pour lemon butter sauce.
Garnish with lemon slices and serve.
In a pan melt the butter over low heat.
Add garlic, salt, black pepper powder and lemon juice. Cook over low heat for a minute. Sprinkle with parsley and red chilli flakes. Set Aside.