Cut the halibut into chunky pieces, discarding the skin and any bones. Season lightly. Crush the cumin and coriander seeds using a pestle and mortar.
Heat the oil in a large frying pan or sauté pan and gently fry the onion and orange rind for 5 minutes. Add the garlic and crushed spices and fry, stirring, for a further 2–3 minutes.
Add the fish, turning the pieces to coat in the spices. Crumble in the saffron and pour in the stock and orange juice. Scatter with the dates and almonds.
Cover with a lid or foil and cook very gently for 20–25 minutes or until the fish is cooked through. Check the seasoning and serve with steamed couscous.