To make the chermoula, put the oil,
garlic, cumin, paprika, three-quarters of
the coriander and the salt in a small bowl.
Add the lemon juice, then blitz with a
hand blender until smooth. Spoon half
over the fish fillets and turn them over to
coat both sides. Set aside to marinate.
Heat the oil and fry the onions and
garlic until softened and starting to
colour, about 4-5 mins. Add the cumin
and paprika and cook for 2 mins more.
Add the tomatoes, stock, olives and
lemon zest, stir in remaining chermoula
and simmer, uncovered for 10 mins.
Stir in the peppers and potatoes,
cover and simmer for 15 mins until the
potatoes are tender. If freezing, reserve
half the sauce and chill before freezing.
Stir the remaining coriander into the
tagine, then arrange the fish fillets on top
(if freezing a batch, reserve 4 portions of
fish), and cook for 4-6 mins until the fish
is just cooked. Serve with basmati rice,
boiled with a little saffron if you like.