Rinse the cod fillets under the tap and pat dry with kitchen paper.
Squeeze the lemon. Finely chop the anchovy fillets and mix with the juice and mustard. You want to end up with quite a thin sauce so, if necessary, add a tablespoon of hot water. Add the oregano and set aside.
Put the oil, and into a frying pan and cook over a medium heat for a couple of minutes.
Add the cod, cover the pan with a lid and cook the fish for 3 minutes on each side.
When the fish is ready, douse with the and mustard sauce and serve immediately.
Notes from the cook
- Fast, fabulous fish given a delicious flavour boost with this easy sauce.