Soak the brains in a bowl of water and salt for a couple hours, or overnight. Drain and rinse, and gently peel off any skin or membrane
Place brains in a fresh pot of cold water with the salt and parsley and bring just to the boil. Simmer gently for 5 minutes, then drain and pat dry
Separate the brain into two lobes and trim neatly. Coat each in seasoned flour, then beaten egg, then breadcrumbs and refrigerate until needed
Cook the peas in simmering salted water for two minutes then drain, reserving half a cup of the cooking water and two tablespoons of peas. Whizz remaining peas to a puree in a blender with butter, sea salt, pepper, and parmesan, adding the cooking water by the tablespoon until light and creamy
Head the oil and fry the crumbed brains until hot and golden, about one minute. Serve on the pea puree, with remaining peas, mint leaves and lemon wedges