Thaw K&N's TenderBrest as per instructions on pack, and season with salt, garlic powder, tarragon leaves, mustard paste, black pepper, olive oil and soy sauce. Mix and leave to marinate for half an hour.
Grease grill pan with oil and grill marinated TenderBrest fillets.
Dish out and serve with Tarragon sauce.
Melt butter in pan and sauté onion. Add water and K&N’s Stok cube, and stir to dissolve.
Add salt, black pepper, tarragon leaves and cream. Stir to mix and cook for 1 minute.