For the mustard sauce (makes 600ml/1 pint):
- 600 ml (1 pint) milk
- 2 bay leaves
- 1 blade of mace
- ½ raw onion
- 40g (1½oz) butter
- 30g (1oz) flour
- 2-3 x 15ml spoon (2-3 tablespoons) wholegrain or Dijon mustard
- 3 x 15ml spoon (3 tablespoons) chopped fresh parsley
- freshly squeezed lemon juice
- salt and black pepper
For the herring:
- 8 x 70g (2½oz) herrings fillets, halved
- 115g (4oz) medium or pinhead oatmeal (NOT porridge oats!)
- maldon salt and black pepper
- a little milk
- sunflower oil, for frying
- To make the mustard sauce: heat the milk until just under boiling point with the bay leaves, blade of mace and the raw onion. Leave to infuse for 20 minutes then strain.
- Melt the butter in a small heavy saucepan. Add the flour and, using a wooden spoon, stir over the heat for about 2-3 minutes, until it turns a sandy brown colour. Take off the heat and using a wire whisk, whisk in the milk all in one go. Make sure it is well blended.
- Stir in the mustard and parsley, taste and season with a little lemon juice, salt and pepper. Cover the surface with cling film and keep warm.
- Season the oatmeal. Dip the herring in a little milk then dip the fish in the oatmeal to coat both sides. Heat the oil in a frying pan and gently fry the fish skin-side uppermost, turning once until lightly browned and crisp on each side - about 5 minutes in all. Serve immediately with the mustard sauce and some crumbly boiled potatoes with plenty of chopped parsley.