Preheat your oven to 200°C. Chop the potato and sweet potato into 2cm chunks (no need to peel). Pop them on a large baking tray in a single layer. Drizzle with oil, then season with salt and pepper. Toss to coat, then spread out and roast on the top shelf of your oven until golden, 25-30 mins. Turn halfway through cooking. Tip: Use two baking trays if necessary, you want the potatoes nicely spread out.

Peel and grate the garlic (or use a garlic press). Zest the lemon and finely chop the chives. Tip: You can snip the chives with scissors if it's easier.

Drizzle the bass with the olive oil for the marinade (see ingredients for amount). Season with salt and half the Cajun spice (don't use all of it!). Rub this onto both sides of the fish. In a small bowl, mix the remaining Cajun spice with half the chives, a pinch of lemon zest, a squeeze of lemon juice and the olive oil for the dressing (see ingredients for amount). Season with salt and keep to one side.

Heat a drizzle of oil in a frying pan on medium heat. Stir-fry the cavolo nero until softened, 4-5 mins. Tip: Add a splash of water and cover with a lid if necessary to help them along. When softened, add the garlic and cook for 1 minute more. Season with salt and pepper to taste. Transfer to a large bowl and cover with foil to keep warm. Wipe the frying pan clean with some kitchen paper, we'll use it to fry the fish.

Heat your (now empty) frying pan on medium-high heat (no oil). Add the sea bass to the pan skin side down and cook until the skin is golden brown, 2-3 mins, then turn over and cook for a further 2 mins. Tip: Don't move the fish while it's cooking skin side down or you won't get a crispy skin! IMPORTANT: The fish is cooked when opaque in the middle.

When the potatoes are cooked, add them to your bowl of greens and mash roughly with a potato masher (or a fork). It won't be smooth but it will be delicious - we call this a 'smash'. Mix in a knob of butter (if you want things extra delicious) and the remaining chives. Season to taste with salt and pepper. Serve your smash on plates topped with the fish and a drizzle of dressing. Enjoy!