Prepare the chermoula: in a blender or mortar and pestle combine Garlic, Cilantro, Parsley, Ground Cumin, Sweet Paprika, Cayenne Pepper, Lemon Juice, Olive Oil, Salt and Black Pepper and pulse to a coarse, spreadable paste; taste and adjust seasoning.
Parboil the potatoes: cut the Potatoes into 1/2-inch slices or cubes, place in a pot with cold Water and a pinch of salt, bring to a gentle simmer and cook 6–8 minutes until just tender but not falling apart; drain and set aside.
Soften the vegetables: heat a little olive oil in a large ovenproof skillet over medium heat and sauté sliced Onion until translucent; add sliced Green Bell Pepper and cook until softened, then stir in chopped Tomato and cook until it begins to break down and form a sauce.
Assemble in the skillet: nestle the parboiled potatoes into the vegetable base, spoon a few tablespoons of the chermoula over the potatoes, then place the Firm White Fish Fillets on top and spread more chermoula over the fish so it is well coated.
Add flavor extras: scatter chopped Preserved Lemon and Green Olives around the fish and potatoes; if the pan looks dry, add a splash of water or extra olive oil to create a little braising liquid.
Cook gently: cover the skillet and cook on the stove over low heat for 8–12 minutes, or transfer to a preheated 375°F (190°C) oven for 12–18 minutes, until the fish is opaque and flakes easily and the potatoes are cooked through.
Finish and serve: drizzle with a touch more olive oil, scatter fresh cilantro and serve immediately with Lemon Wedges for squeezing over each portion.
