Preheat your oven to 220°C/200°C fan/gas mark 7. Put a large saucepan of water with ½ tsp salt on to boil for the potatoes.

Meanwhile, trim the carrots, then halve lengthways (no need to peel). Chop into roughly 1cm wide, 5cm long batons. Pop the carrots onto a large baking tray. Drizzle with oil, season with salt and pepper, then toss to coat. Spread out in a single layer. 

When the oven is hot, roast the carrots on the top shelf until tender, 20-25 mins. Turn halfway through.

Meanwhile, chop the potatoes into 2cm chunks (peel first if you prefer).

When your pan of water is boiling, add the potatoes and cook until you can easily slip a knife through, 15-20 mins.

While the veg cooks, halve, peel and chop the shallot into small pieces. Peel and grate the garlic (or use a garlic press).

Pop the breadcrumbs and pesto into a small bowl. Drizzle in a little olive oil and mix together. 

Pat the basa dry with kitchen paper. Lay onto another lined baking tray. Season with salt and pepper. 

Spoon the pesto crumb evenly over the fish, pressing it down with the back of the spoon.

Pop the basa on the top shelf of your oven until cooked through, 10-12 mins. IMPORTANT: Wash your hands and equipment after handling raw fish. It's cooked when opaque in the middle.

Meanwhile, heat a drizzle of oil in a medium frying pan on medium heat.

Once hot, add the shallot and stir-fry until softened, 4-5 mins. Stir in the garlic and cook for 30 secs. Add the cider vinegar and allow it to evaporate, 1-2 mins.

Pour in the water for the sauce (see ingredients for amount) and veg stock paste, then bring to the boil and simmer until reduced by half, 2-3 mins.

Vigorously stir in the butter (see pantry for amount) until melted, then take off the heat.

Pop the spinach into a colander in your sink.

Once the potatoes are cooked, pour the potatoes and water over the spinach in the colander, until the spinach is wilted and piping hot. Return to the pan, off the heat.

Add a knob of butter and a splash of milk (if you have any) and mash until smooth. Season with salt and pepper. 

Serve the basa with the garlic butter sauce spooned over and the spinach mash and roasted carrots alongside.