Preheat your oven to 200°C/Fan 180°C/Gas 6. Scrub the potatoes. If your potatoes are around the size of a medium egg, keep them whole. Otherwise, halve or quarter them so they're all roughly the same size.

Place 1 potato in a serving spoon or a wooden spoon – this helps to keep it steady. If it is halved or quartered, then place it flat side down. Slice the potato at 3mm intervals, but don’t slice all the way down. Make sure the bottom 1cm of each potato is unsliced.

Place a large roasting tin over a couple of hobs. Add the butter with 1 tsp oil. Season with a good pinch of salt and pepper. Warm over a medium heat to melt the butter, then add the potatoes and turn them once or twice, spooning the butter and oil over them so they are well coated. Slide the potatoes into the oven and cook for 45-50 mins, basting occasionally, till golden and crisp on the outside with tender middles.

Meanwhile, trim the woody stalks from the spring greens and roughly shred the leaves. Trim any tough ends from the purple sprouting broccoli and slice any thick stalks into smaller pieces (you can leave on the leaves). Peel the red onion and thinly slice it. Peel and thinly slice the garlic clove.

When the potatoes have about 15 mins cooking time remaining, remove them from the oven and rub them with a pinch of salt and pepper. Make two gaps and nestle the salmon into them, before sliding the tin back into the oven. Cook for 15 mins, till the fish is flaky and cooked through.

Pour 1 tsp oil into a medium pan and warm to a medium heat. Slide in the chopped onion and cook for 5 mins, till slightly softened. Add the garlic, spring greens and purple sprouting broccoli to the pan, along with 2 tbsp water. Fry for a further 5 mins, till tender. Squeeze in the lemon juice and stir well to combine.

Divide the salmon, hasselback potatoes and greens between plates and serve.