Braised tails and trotters: Sweat off all aromatics in vegetable oil until vegetables begin to soften. Add white wine and reduce by half then add beef demi. Add the trotters and tails and cover with water. Bring the liquid to the boil then simmer for approx 3 hours or until the meat just falls away from the bone. Remove tails and trotters and place on a tray to cool slightly. With your hands and a small knife make an incision down the length of one side of the tails and trotters peeling the skin away from either side and ensure no little bones are left. Place on a flat tray between a layer of greaseproof paper and ensure they are flat and refrigerated before assembly. Strain liquid through a fine chinois and reduce liquid by ¾ and set aside warm ready for terrine assembly.
Pork neck: Place pork neck into a cryovac bag along with aromatics, salt and olive oil, seal. Place into a water bath @ 75°C for 12 hours. Remove pork from the bag and with your hands pull apart the pork neck into 5 cm long pieces and place into a bowl. Add reduced tail & trotter liquor, parsley, apple vinegar & salt to taste. Set to the side ready for assembly.
Leeks: Cut leek pieces length ways separating all the layers and wash under cold water, ensuring they are free from grit. Bring a pot of salted water to a rolling boil. Add leeks and cook until they become slightly softened then place into iced water. Layer the leeks between sheets of Chux or paper towel to dry.
Assembly of terrine: Line the terrine mould with cling wrap and then a layer of the prepared leeks. Add a 2cm layer of pork neck mix. Add a layer of your pigtails end to end. Add another 2 cm layer of pork neck mix. Add the layer of pig trotter end to end. Add the final layer of pork neck mix covering the trotters. Fold over the leeks and cling wrap and place a small weigh on top and refrigerate overnight.
Burnt Onion Dressing: Place onions on char grill or skillet and grill until slightly blackened not burnt. Chop onions; add vinegars, oil and season with salt and pepper.
Apple Crisps: Slice apples thinly on a mandolin and place into a water and sugar solution of 10:1 ratio for 2 hours. Dry off and place in dehydrator or oven @50°C overnight.
Garnish: Plate a single slice of the terrine, garnish with apple crisps, nigella seeds, rocket flowers and mustard leaves.