Preheat a griddle pan over medium/ high heat.
Once hot, drizzle a little of oil on the griddle and season the filets with salt and pepper.
Place the filet on the griddle and sear for 2 minutes without moving the fishes.
Then, using a fish lifter or flat spatula, turn the fish and continue to grill for a further 2 minutes.
Add this stage, add the cold butter and allow to melt, foam and brown slightly to give the ‘beurre noisette’ flavour.
Turn off the heat and squeeze over the lemon juice and sprinkle the coriander.
Baste the fish fillets with a spoon for 30 -45 seconds to coat the beurre noisette in the fish.
Serve the fish immediately with slices of fresh bread or some steamed new potatoes and a small drizzle of the beurre noisette.