Roast jersey royal, spring herb, hazelnut and bacon salad with lemon brown butter dressing

Method

1. Heat the oven to 200°C/180°C fan/gas 6. Toss the potatoes in the olive oil and spread over the base of a large roasting tin so they aren’t crowded. Season well with salt and pepper, then roast for 30 minutes. Scatter the bacon over the top, then roast for another 20 minutes. Scatter over the hazelnuts and return to the oven for another 5-8 minutes. The potatoes should be shrivelled on the outside and fluffy in the centre, the bacon crisp and the hazelnuts golden. Leave in the oven, heat off, to keep warm.
2. Meanwhile, put the watercress, herbs and radishes in a large bowl.
3. For the dressing, heat a small, heavy-based saucepan over a medium heat, then gently melt the butter with some sea salt. Turn up the heat to bring the butter to a bubble, then cook until it turns golden brown and smells nutty. Remove from the heat, then add the oil, garlic and the juice of ½ lemon – it will sizzle. Cool slightly, then taste – add the remaining lemon juice if it needs to be sharper.
4. Working quickly, tip the potato mixture into the salad bowl, then drizzle over the hot butter dressing (if you’d like a less pungent dressing, strain the butter to remove the garlic first). Toss well, taste one of the leaves and season if necessary. Serve immediately.