Prep 5 min
Cooking 25-30 min
Serves 4
½ red onion (about 60g), peeled and very finely sliced (use a mandoline if you have one)
1½ tbsp sherry vinegar
2 tsp caster sugar
½ tsp mustard seeds
½ tsp coriander seeds
⅛ tsp black peppercorns, roughly crushed
¼ tsp pink peppercorns
½ red chilli, deseeded and finely sliced
Salt and freshly ground black pepper
3 leeks, trimmed, cut in half lengthways and then into 6cm-long pieces (450g net weight)
60ml olive oil
1 bunch spring onions, trimmed, cut in half lengthways and then into 6cm-long pieces (75g net weight)
60g mascarpone
30g dolcelatte (or gorgonzola dolce)
1½ tbsp double cream
5g chives, cut into 2cm lengths
Put the first eight ingredients in a small bowl with an eighth of a teaspoon of salt. Thoroughly massage the onions in the mixture, then leave to pickle for at least an hour.
Heat the oven to 200C/400F/gas mark 6. Lay the leeks cut side up on a 25cm x 35cm oven tray and season with a quarter-teaspoon of salt and plenty of black pepper. Drizzle over two and a half tablespoons each of the oil and of cold water, and roast for 15 minutes, until the leeks are beginning to soften and blacken around the edges. Scatter the spring onions over the leeks, add a pinch of salt and half a tablespoon of oil, and return to the oven for eight minutes. Turn the oven grill to its highest setting, then grill the vegetables for four minutes until they are charred and soft, but not burned. Leave to cool.
In a small bowl, whisk the mascarpone, dolcelatte, cream, a pinch of salt and a good grind of pepper until combined and smooth.
Once the leeks and spring onions are cool, use a fish slice to slide them on to a serving platter (so keeping the leeks cut side up). Drop dollops of the cheese-and-cream mixture haphazardly all over the vegetables.
Combine the chives with the remaining tablespoon of oil, then dribble all over the top of the vegetables and cheese. Spoon on the pickled onions (including their pickling liquid and aromatics), and serve at room temperature.
