Heat 1 tbsp of olive oil in a wide, shallow
pan. Add the onion, celery, garlic, anchovy
(if using) and chilli flakes. Season and cook
for 10 minutes. Add the tomatoes and cook
for another couple of minutes. Pour in the
wine and stock and bring to a boil. Cook for
2 minutes then add the couscous. Turn
down to a simmer and add the fish.
Cover with a lid and cook until the
fish is done, about 5-7 minutes.
Divide between 2 dishes, breaking
the fish into large pieces. Sprinkle
over lemon zest and parsley to finish.