For the ham hock:
The ham hock can be cooked ahead of time and reheated in some of the cooking liquid. Rinse the hock and place in a deep pan with the carrot, onion, leek, bay and peppercorns. Cover with cold water and bring to the boil. Reduce the heat to a gentle simmer and cook until completely tender. The small bone will pull out easily and cleanly when done. Allow to cool in the stock for an hour, then remove and flake the meat from the bone in large chunks. Discard any sinew and excess fat. Reserve some of the cooking liquor if you are reheating later.
For the charred corn:
Smear the corn with oil, rubbing it in well and then season with salt. Char on a chargrill or griddle pan until blackened all around the cob. Allow to cool and carefully slice off the kernels of corn, keeping them as whole as possible.
For the mustard dressing:
Mix the lecithin with a tablespoon of hot water in a jug, then whisk in the honey and mustard. Add a generous pinch of salt and a few grinds of black pepper. Using a hand blender, gradually add the oils. If the dressing gets too thick, add some of the vinegar as you mix. Once all the oil has been incorporated, add the remaining vinegar and season to taste. Depending on the vinegar and how sharp you like your dressing, you may not need all the vinegar.
To serve:
Mix the potato cubes with a few tablespoons of the dressing, season to taste and stir in the parsley. Break down the chicory into individual leaves and slice into pieces. Reheat the ham hock if necessary. Place a line of chicory leaves across the plates and divide the corn and potato salad between them. Add chunks of ham to the salads, top with the popcorn shoots and drizzle over some more mustard dressing.