Preheat the oven to 220C, fan-forced. Line 1 large oven tray and 1 oven tray with baking paper. Cut the unpeeled potatoes into 5mm-thick slices. Scrub and trim the Dutch carrots.
Step 2 — Roast potato
Put the potato on the large lined tray, drizzle with 2 tsp olive oil, season with salt and pepper and turn to coat. Roast on the upper oven shelf for 25 mins or until golden and tender.
Step 3 — Roast carrots
Put the carrots on the remaining lined tray, drizzle with 2 tsp olive oil and 2 tsp honey, season with salt and pepper and turn to coat. Roast on the lower shelf for 25 mins or until tender.
Step 4 — Make pea puree
Meanwhile, bring a small saucepan of water to the boil. Add the peas, return to the boil and cook for 1 min. Drain. Put the peas, 15g butter and 1 tbs water in a tall jug. Blend with a stick blender until smooth. Taste, then season well with salt and pepper.
Step 5 — Cook fish
When the vegetables have roasted for 15 mins, pat the fish dry with paper towel, rub with 2 tsp olive oil and season with salt and pepper. Heat a small frypan over medium-high heat until hot. Cook the fish, skin-side down, covered, for 3 mins. Turn and cook, uncovered, for 4 mins or until cooked through (cooking times may vary depending on thickness of fillets).
Step 6 — Get ready to serve
Scatter the dukkah over the roast vegetables. Divide the pea puree, roast vegetables and fish among plates to serve.