1. Process garlic, spices, coriander or parsley, lemon zest and juice together with 1 tablespoon of olive oil. Cut fish in large chunks and place in a ceramic dish. Smear with spice mixture and leave to marinate for 30 minutes.
2. Cook potatoes in boiling, salted water for 5 minutes until half cooked. Place potatoes, red pepper, artichoke hearts and olives in the base of a tagine or casserole dish and pour over fish stock.
3. Arrange pieces of marinated fish on top, with the marinade juices. Sprinkle with salt and pepper and drizzle with a tablespoon of olive oil. Bring to the boil, then turn down heat, cover and simmer very gently for 15 minutes. Serve immediately.

Tip: A tagine is both the name of a stew-like dish and the specialised ooroccan cooking pot with a shallow base and a conical lid, in which the dish is cooked. Traditionally cooked over a charcoal brazier, the tagine can also be set over a low gas or electric element. A standard flameproof casserole dish makes a suitable substitute.