This very simple way of cooking fish locks in all the flavour and moisture. Delicious served with spinach - try it with rosemary potatoes if you're hungry.
Preheat the oven to 180°C. Score the skin of the herring by making slashes into the skin of the fish, then season with salt and pepper.
In a small pan mix the melted butter, crushed garlic, lemon rind, mustard, lemon juice and parsley, season.
Place the herring on hot griddle pan and brush with the mustard butter, cook for 2 minutes then turn over the fish and brush the other side with the mustard butter.
Whilst the fish is cooking on the griddle insert one slice of lemon and one sprig of rosemary into the cavity of each fish.
Place a large sheet of foil on to a baking tray. Tip the remaining mustard butter on to the foil the top with the griddled fish. Close the foil parcel and seal then bake in the oven for 10 minutes.
Arrange the baby spinach on a plate with a slice of lemon then place the herring on top and pour over the hot mustard butter from the foil to serve.
