Arrange the joints in a shallow dish large enough to hold them in a single layer.
In a mortar grind the garlic with 1 heaped tsp sea salt and crush to a paste. Add to the eggs, season with pepper and whisk together until well blended.
Pour the egg over the chicken joint, cover with clingfilm and refrigerate for at least four hours, turning halfway.
Preheat the oven to 180 C, Gas 4. Put in a large shallow roasting tin containing the butter and oil to preheat.
Meanwhile combine the breadcrumbs with the parmesan, parsley and a little seasoning together on a plate. Spead out some absorbent kitchen paper on a flat surface.
Remove chicken from fridge. Take one piece at a time and carefully sit it in the crumb mixture, patting and coating all over with crumbs. As each piece is coated lay on the kitchen paper.
Remove the roasting tin from the oven and add the chicken pieces. Baste and bake on a high shelf for 20 mins, then turn over and cook for 20 minutes more. Pour off the excess fat and cook for a further 5 minutes.
Drain on kitchen paper then serve hot or leave to cool.