Roasted Mackerel with Beetroot and Potatoes
A sheet-pan traybake of golden roasted potatoes and sweet beetroot, with mackerel fillets laid on top to cook gently. Finished with fresh dill and a sharp horseradish dressing.
- Total
- 52 min
- Prep 15 · Cook 37
- Serves
- 1
- Difficulty
- Easy
You'll practice: Roasting · Dicing
- Savory
- Stovetop
- Oven
Instructions
-
Heat the oven to 220°C (200°C fan). Cut the potatoes into 2 cm cubes and the beetroot into 2 cm cubes.
~10 min
Cutting vegetables into uniform 2 cm cubes ensures they cook at the same rate, preventing some pieces from burning while others stay raw.
If your beetroot is large, cut it into smaller 1.5 cm cubes than the potato so both finish cooking at the same time.
Dicing Cut potatoes and beetroot into uniform 2 cm cubes for even cooking. Use a sharp knife and steady guide hand for consistent size.
-
Put the potatoes and beetroot on a large baking tray. Drizzle with 1.5 tbsp olive oil, season with 0.75 tsp salt and 0.25 tsp black pepper, and toss to coat. Spread everything in a single layer.
~5 min
Coating vegetables in oil and seasoning before roasting helps them brown evenly and prevents sticking to the tray.
-
Roast for 25 minutes, turning the vegetables once halfway, until the potatoes are golden at the edges and the beetroot is tender when pierced with a knife.
~25 min
Roasting at high heat caramelizes the natural sugars in the vegetables, creating a golden crust and deeper flavor.
Roasting Roast vegetables in a single layer with space between pieces so they brown, not steam. For fish, roast until opaque and flaky, about 8-10 minutes.
-
While step 3 cooks
While the vegetables roast, mix the horseradish with 0.5 tbsp olive oil, 0.25 tsp salt and 0.25 tsp black pepper in a small bowl. Chop the dill.
~5 min
-
Pat the mackerel fillets dry and season with the remaining 0.25 tsp salt and 0.25 tsp black pepper. Push the vegetables to the sides of the tray and lay the fillets skin-side up in the centre. Roast for 8 to 10 minutes, until the fish is opaque and flakes easily with a fork.
~10 min
Placing mackerel skin-side up exposes it to direct oven heat, crisping the skin while the fish cooks gently on top of the vegetables.
Laying the mackerel on top of the vegetables rather than underneath keeps the skin exposed to the oven's heat so it crisps instead of steaming.
Roasting Roast vegetables in a single layer with space between pieces so they brown, not steam. For fish, roast until opaque and flaky, about 8-10 minutes.
-
Serve the mackerel and vegetables on warm plates, spoon over the horseradish mixture and scatter with the chopped dill.
~2 min