In a bowl combine marinade ingredients, olive oil, minced garlic, salt, pepper, lemon juice, white wine, tarragon and chives.
Arrange fish fillets in a single layer in a shallow glass pan. Pour marinade over fish, cover and refrigerate for an hour.
Remove from fridge and let stand for 20 mins.
Preheat Bradley Smoker to between 100-120°C. Using Alder flavour bisquettes smoke/cook for approximately 60mins, checking periodically to make certain you do not overcook.
For the horseradish mayonnaise, combine the mayonnaise, horseradish and a good squeeze of lemon juice. Season with salt and pepper.
Light a CobbleStone and wait a few minutes until it has turned grey.
Place the Frying Dish onto the Cobb Cooker and close the Dome Cover for at least 5 minutes until the pan is hot.
Cut the potatoes into thin rounds, leaving the skins on.
Add the potatoes to the Frying Dish and just cover with water.
They will take about 30-45 minutes to cook through.
When they are cooked, remove and drain them from the water (making sure all the water is gone as you want quite a dry mash). Mash the potatoes with the butter and season well.
Place the Frying Pan on the Cobb Cooker and let it heat up for at least 5 minutes with the Dome Cover on.
Fry the fish in a little olive oil with the Dome Cover on and then remove and add to the mash mixture.
Wipe the Frying Pan and place back onto the Cobb Cooker.
Add the fresh herbs, lemon zest, flour and a good pinch of salt and black pepper to the mash mixture and combine well.
Shape into fish cakes.
Add a good glug of olive oil to the pan and gently add your fishcakes.
Let them cook for about 10 minutes on each side until they are crisp and golden.
Serve with tangy horseradish mayo and a fresh green salad or enjoy with your favourite side dishes.