Scrub the potatoes and chop them into bite-sized chunks. Slide the potatoes into a large pan and cover with cold water. Add a pinch of salt and pop on the hob. Bring to the boil, then cover the pan with a lid and reduce to a simmer. Cook for 15 mins, till the potatoes are tender.

Preheat your oven to 200°C/Fan 180°C/Gas 6. Trim the roots and top 3cm off the leeks. Slice a cross into the top of each leek to open them out and rinse out any grit. Slice the leeks on the angle into small, bite-sized pieces and scatter into a roasting tin. Trim the spring onions and also slice into bitesized pieces. Add to the leeks.

Nestle the pollack fillets among the leeks and spring onions. Sprinkle over a generous pinch of salt and pepper and drizzle with 2 tsp olive oil. Slide into the oven for 15 mins, till the fish is flaky and cooked through, and the leeks have softened.

Meanwhile, peel the garlic clove and finely grate it into a bowl. Squeeze in the juice from the lemon and stir in 1 tsp olive oil.

Drain the cooked potatoes and allow to steam dry in the colander for 1 min. Divide the potatoes between plates. Top with the roasted leeks and spring onions and add a fillet of pollack. Spoon over the garlic and lemon dressing and serve.