Salt marsh lamb with tidal greens

In England, the benefits of salt marsh grazing have been known since the 13th century, yet for many years the vast majority of the meat has been exported to France, where it is recognised as a delicacy. However, salt marsh lamb is once again becoming available here. Farmers with coastal pasture bring their flock to the sea marshes in spring so the sheep can graze close to the water's edge, feeding on sea vegetation such as samphire, sorrel, sea lavender and thrift.

Serves 6-8
anchovies 1 tin, drained
shoulder of salt marsh lamb, boned about 2kg
rapeseed oil
onions 4, cut into quarters
large carrots 4, peeled but left whole
spears of rosemary 4
parsley a bunch
head of garlic 1, cut in half through its equator
dry vermouth 200ml
new potatoes 1kg
butter a knob
mint a small bunch, chopped

For the salt marsh greens
spinach or kale a bunch
sea kale (can be replaced with purple sprouting broccoli) a bunch
fat hen (can be replaced with spinach) a bunch
butter a knob

Heat the oven to 160C/gas mark 3. Spike the lamb in several places with a small knife, working it under the top layer of the flesh laterally rather than downwards. Push the anchovy fillets into the incisions. They will dissolve during the long cooking process, seasoning the meat and negating the need to salt the joint further. Even if you are not keen on these rich, salty and umami fish fillets, we urge you not to omit them. The final flavour will not be of fish but of seasoned lamb.

Heat a thin film of rapeseed oil in a large, heavy-based frying pan, add the lamb shoulder and sear over a high heat until browned all over. Put the onions, carrots, rosemary, parsley and garlic in a roasting tin and place the lamb on top. Pour in the vermouth, cover with foil and place in the oven. Roast for 3½-4 hours, until you have a tender roast of the highest order. Remove from the oven and leave to rest for at least 20 minutes.

Scrub the potatoes and cut them so they are all roughly the same size. Cook in boiling salted water until tender, then drain and toss with butter and mint.

Wash the greens then blanch them whole in fast-boiling, well-salted water for 1 minute. Drain and toss with butter. Serve with the lamb and potatoes.

Sweet-cure mackerel with morels, spelt soda bread and horseradish

Choose line-caught mackerel and make sure they are very fresh.

Serves 4
mackerel fillets 4, pin bones removed
dried morel mushrooms, or ceps 10g
cider vinegar 400ml
aniseed 1 tbsp
caster sugar 300g
fine sea salt

For the spelt soda bread
brown spelt flour 200g
white spelt flour 200g
fine oatmeal (or use porridge oats that have been blended until fine) 50g
bicarbonate of soda 1 tsp
salt 1 tsp
honey 1 tbsp
buttermilk (if unavailable, mix 25ml white vinegar with 350ml milk and leave to rest for 5 minutes) 375ml
butter, melted 25g

For the horseradish sauce
horseradish root 1, finely grated
cider vinegar 2 tbsp
crème fraîche or soured cream 4 tbsp
chopped chives 1 tsp
chive flowers 1 tsp
sea salt

Lay the mackerel fillets flesh-side down on a bed of fine sea salt and chill for 2 hours to cure, then rinse. This gives a firmer-fleshed result. Rehydrate the mushrooms by steeping them in near-boiling water with a splash of the vinegar for 10 minutes. Strain, reserving the liquor, and then check each one is free of soil and sand. The liquor that remains will be delicately smoky and truly flavoursome.

Warm the aniseed through in a dry pan until it spits and cracks, then carefully pour the mushroom liquor into the pan, leaving any residue of soil or sand behind. It will boil up rapidly as it hits the hot pan, so take care at this point. The evaporation will intensify the flavour of the mushroom stock. Add the vinegar and heat through then add the sugar and stir until dissolved.

Add the mushrooms and remove from the heat. Allow this mixture to cool, then pour it over the fish. Place in the fridge for at least 2 hours and up to 6. The simple-to-make spelt soda bread can fill this gap quite comfortably.

Heat the oven to 200C/gas mark 6. Mix all the dry ingredients for the bread together in a large bowl, then make a well in the centre. Add the honey, buttermilk and melted butter to the well and mix with a wooden spoon until well combined. Put the dough into a 900g loaf tin (or a 23cm springform cake tin) lined with baking parchment and place in the oven. Bake for 15 minutes, then reduce the oven temperature to 160C/gas mark 3 and bake for 30 minutes longer. Turn the loaf out on to a tea towel and tap the base; it should sound hollow. If necessary, return to the oven for a few minutes longer. Cool the loaf on a wire rack, covering it with a tea towel if you prefer a soft crust.

To make the horseradish sauce, combine the horseradish, vinegar and a pinch of sea salt. Strain through a sieve, discarding the liquid, then combine with the crème fraîche or soured cream. Season to taste with salt and top with the chives and chive flowers. The mackerel can now be lifted from its souse and served with buttered soda bread and the irresistible horseradish.

Extracted from The Ethicurean Cookbook by Matthew Pennington, Iain Pennington, Paûla Zarate and Jack Adair Bevan, published by Ebury Press at £25 on 16 May 2013. To order a copy for £20 with free UK p&p go to guardian.co.uk/bookshop