Preheat the oven to 240°C/220°C fan-forced. Cut the potato into bite-sized chunks. Place on a lined oven tray. Drizzle with olive oil, sprinkle with the brown mustard seeds and 1/2 the Sri Lankan spice blend. Season with salt and pepper. Toss to coat. Bake until tender, 20-25 minutes. TIP: If your oven tray is crowded, divide the potatoes between two trays.

While the potatoes are baking, grate the carrot. Thinly slice the cucumber into half-moons. Roughly chop the coriander.

When the potatoes have 10 minutes remaining, rub both sides of the barramundi with the salt, a good pinch of pepper and the remaining Sri Lankan spice blend.

In a large frying pan, heat a drizzle of olive oil over a medium-high heat. Cook the barramundi until just cooked through, 3-4 minutes each side. TIP: Barramundi is cooked through when it turns from translucent to white.

While the barramundi is cooking, combine the carrot and shredded cabbage mix in a medium bowl. Add the mayonnaise and a drizzle of white wine vinegar. Season, then toss to coat.

Divide the spiced potatoes and cucumber slaw between plates. Top with the Sri Lankan-style barramundi. Garnish with the coriander to serve.