Boil potato slices in salted water for about 6 minutes, drain, and set aside.

Trim and slice fennel bulbs; save fennel fronds.

Slice lemon and halve cherry tomatoes.

Pit or crush olives (you can skip pitting, though it’s easier to eat without).

In a large bowl, mix potatoes, fennel, lemon, tomatoes, and olives.

Drizzle with olive oil and cider vinegar, season with salt and pepper. Gently toss to coat evenly.

Lightly oil the base of a tajine or oven-safe dish.

Layer in the vegetable mixture.

Remove skin and bones from haddock.

Rub fillets with olive oil, lemon juice, salt, pepper, coriander, and garlic powder.

Place fish on top of vegetables.

Cover with the tajine lid (or oven-safe lid), bake at 180 °C (350 °F) for 20 minutes.

Remove fish, cover again, and bake vegetables alone for another 25–30 minutes, until tender.

Return haddock to the top before serving. Garnish with fresh fennel fronds and a squeeze of lemon.