Ingredients
For the mustard seed oil
50g/2oz yellow mustard seeds
½ white onion, chopped
2 garlic cloves, roasted, skin removed
300ml/10fl oz sunflower oil
For the caramel syrup
100g/4oz sugar
50ml/2fl oz water
30ml/1fl oz fresh lime juice
For the lamb
1 loin salt marsh lamb, fully trimmed of fat and sinew
10g/½oz roast onion powder (substitute onion powder if unavailable)
For the lamb sweetbreads
4 lamb sweetbreads
1 medium onion, finely chopped
2 cloves
1 bay leaf
handful parsley stalks
salt
1 tsp icing sugar
2 tbsp clarified butter
For the pickled red cabbage
2 tbsp mustard oil (see recipe above)
50g/2oz carrots, finely chopped
50g/2oz onions, finely chopped
salt and freshly ground black pepper
1 red cabbage
55g/2oz coarse sea salt
150ml/5fl oz bilberry and African basil-infused vinegar
250ml/9fl oz malt vinegar
150ml/5fl oz white wine vinegar
150ml/5fl oz balsamic vinegar
400ml/14fl oz red wine
300g/10½oz caster sugar
2 star anise
5 bay leaves
10 whole cloves
1 tsp whole black peppercorns
1 tsp whole pink peppercorns
1 cinnamon stick
5 whole dried red chillies
For the potato crisps
300ml/½ pint vegetable oil, for deep frying
1 Maris Piper potato
To serve
2-3 large spring onions, finely sliced
small bunch wild summer leaves, trimmed, washed and dried
pea shoots and asparagus shoots
squeeze fresh lemon
small handful chives, chopped
salt
freshly ground black pepper

Method
1. For the mustard seed oil, grind the mustard seeds in a pestle and mortar. Place in a small heavy-based pan, add the onion and garlic, cover with oil and cook over a very low heat for 6-10 hours stirring occasionally to prevent sticking. Cool, then blend with a hand blender until smooth.
2. For the caramel syrup, place the sugar, water and lime juice into a small pan, place over a moderate heat and leave to simmer. As soon as the mixture turns golden-brown, remove from the heat.
3. For the lamb, dust the lamb loin with the onion powder, and then roll the lamb tightly in several layers of cling film. Prepare a steamer and steam the lamb for nine minutes. Set aside and allow to rest for five minutes.
4. For the sweetbreads, run the sweetbreads under cold water. Then place them in a non-reactive bowl of cold water and keep changing the water every five minutes or so for at least two hours to release any blood from them. Place the sweetbreads in a heavy-based pan, barely cover with water, add the onion, cloves, bay leaf and parsley stalks then season with salt (it is very important to make sure the water is well seasoned, but not over seasoned). Bring up to the boil, skim and allow to simmer for five minutes. Remove from the heat and leave to cool in the stock. Remove and refrigerate. When ready to serve, dust the sweetbreads in icing sugar. Heat the clarified butter in a pan, add the sweetbreads to the pan and fry for one minute each side.
5. For the pickled red cabbage, heat two tablespoons of the prepared mustard oil in a large saucepan, add the carrots and onions, and gently fry for a few minutes. Season with salt and freshly ground black pepper and leave to cool. Meanwhile, half and quarter the red cabbage, remove the large stem in the middle and finely slice the red cabbage leaves or chop in a food processor. Place the red cabbage into a colander, cover with the sea salt and leave for two hours or until a deep rich colour is achieved. Drain and wash all the salt away thoroughly and pat dry with kitchen paper. Place all the vinegars, wine and sugar in a non-reactive pan, place over a medium heat and boil until the volume of liquid has reduced by half.
6. Place all the remaining spices into a pestle and mortar or coffee grinder and grind coarsely.
7. When the reduction is near completion, place all the ground dry spices into the reduction and allow to infuse for five minutes. Pass the reduction through a fine sieve and, while hot, pour onto the red cabbage in a suitable container. Leave the red cabbage out overnight to cool and then refrigerate.
8. For the potato crisps, pour the vegetable oil into a large saucepan and heat until a small cube of bread turns golden-brown in 30 seconds. (CAUTION: do not leave hot oil unattended as hot oil can be dangerous.) Finely slice the potato on a mandoline and dry with kitchen paper. Carefully drop the potato slices into the hot oil and fry until golden-brown and crisp. Remove with a slotted spoon and drain on kitchen paper.
9. To serve, place two spoonfuls of red cabbage onto each of four plates. Remove the lamb from the cling film, keeping the juices, and then cut the loin in half lengthways and then again in half across giving four portions in total. Place a piece of loin on top of the red cabbage and place a sweetbread alongside.
10. Place the chopped spring onions, summer leaves, a little of the remaining mustard oil, a squeeze of lemon juice and the lamb juices into a bowl (the rest of the mustard oil can be covered and set aside for 2-3 days to use for another dish). Mix together and season with salt and freshly ground black pepper. Divide the dressed leaves equally among the plates, garnish with the potato crisps and serve immediately.