Prepare salsa. Chop tomatoes, cucumber, onions and coriander combine and place into a bowl.
Wash and prepare lettuce rinse well and leave to drain.
Lightly flour fish fillets. Heat butter in Pan and lightly fry fillets until golden.
Fill warmed tortillas with lettuce and salsa. Top with fish pieces. Serve with sour cream or Tartare and lemon/lime wedges.