Anchovy fillets

Anchovy salt-cured for months, then packed in oil. During the cure the fish's own enzymes break protein down to free glutamate and the RNA down to inosinate. Together these give strong umami. Chop fine or mash. In a raw dish the anchovy should not be tasted as fish. It should make the beef taste more savoury. It is salty, so count it as part of the salt.