Oven-Baked Mackerel on Potatoes with Garlic and Olive Oil

Baked mackerel on potatoes starts with prebaking the potato slices. Preheat the oven to 200 °C (390 °F). Wash, peel and slice the potatoes into thin rounds about 3 mm thick. Spread the slices in an oiled baking dish and add the garlic slices. Drizzle with 2 tablespoons of olive oil and season with salt and pepper. Toss to coat, then bake for 20 minutes.

Pat the mackerel dry inside and out with paper towels. Rub each fish with the remaining tablespoon of olive oil, season with salt and pepper, and stuff the cavity with thyme sprigs and garlic slices. Squeeze the juice of half a lemon over the fish.

Remove the par-baked potatoes from the oven and give them a stir. Place the mackerel directly on top of the potato bed and return to the oven for a further 20 to 25 minutes. The fish is done when the skin is golden and the flesh flakes easily from the bone. Serve immediately with slices of the remaining lemon and a scattering of chopped parsley.