1.Heat oil in tagine or saucepan over medium-high heat. Gently fry onion for 5 minutes until beginning to soften. Add garlic and spices. Cook for a further 2 minutes.
2.Stir through tomatoes, stock, lemon rind and olives. Remove half of mixture and place in bowl.
3.Season fish with salt and pepper and lay it over mixture still in saucepan. Top with remaining mixture from bowl. Cover with lid, reduce heat to medium-low and cook for 12 minutes until fish is just translucent. Scatter coriander leaves over top.
4.Meanwhile, boil kettle. Pour couscous into large mixing bowl and top with knob of butter. Season with salt and pepper to taste. Pour boiling water over couscous and cover bowl tightly with cling wrap. Allow to stand for 3 minutes.
5.Remove cling wrap from couscous, add almonds and fluff with fork. Serve with fish tagine.