Begin, ahead of time, by making the gooseberry sauce. Heat a small pan and once hot, add the mustard seeds to toast. Once they start to pop, decant into a small bowl and reserve.
Heat the olive oil and add the fennel and shallot, plus the sea salt. Cook gently until the shallot is transparent and the fennel has begun to soften.
Add the pepper, dried thyme, vegetable stock and water. Bring to a simmer and cook until the fennel is tender.
Taking a stick blender, carefully blend until thoroughly combined, but still retaining texture. Decant into a bowl and reserve. Replace the pan onto the heat.
Add the gooseberries directly to the pan and add a tablespoonful of water. Cover the pan and allow the gooseberries to heat through, giving the pan a little shake every now and then, to prevent them from sticking. This should only take around 5 minutes if the gooseberries are ripe.
Once the berries are softened and their juice is beginning to escape, add the fennel mixture and mustard seeds and stir to combine.
Add the sugar and remaining 50ml of water. Stir well, then bring to a simmer and cook until the sauce has reduced to a loose jammy consistency. Taste for seasoning and adjust if necessary, likewise if you think the sauce needs more sugar, correct that too. Be cautious with the sugar, as you want the sauce to stay tart and not become jam-like.
Once you are happy with the flavour and consistency, decant into a bowl and allow to cool.
Remove the pork from the fridge a good half hour ahead of time.
Place into a roasting tin and mix the seasoning ingredients (oil, paprika, thyme, garlic, lemon juice, salt and pepper) together.
Spoon the seasoning mix over the top of the pork and rub into all the cracks and crevices.
Put into a pre-heated oven at 180degC/350degF/Gas 4 for an hour and a half.
Remove the pork from the oven and baste it with the juices, then cover with tinfoil and return to the oven.
Turn the oven down to 130degC/250degF/Gas 2 and cook for another hour.
Remove the pork from the oven and baste it again, then replace the tinfoil and leave it in a warm place to rest for 30 minutes, before carving.