To make the marinade, combine the garlic, sugar, sauces, oil and whisky or sherry in a ziplock bag. Stir in the lemon grass and scallions. Add the pork chops, turning to coat them in the marinade. Cover and leave to marinate for 1-2 hours, and up to 24 hours for the most flavour.
Lift the chops out of the marinade and place them on a barbecue over hot coals or on a grill (broiler) rack. Add the mushrooms and brush them with 15 ml/1 tablespoon of the oil. Cook the pork chops for 5-7 minutes on each side and the mushrooms for about 2 minutes. Brush both with the marinade while cooking.
Heat the remaining oil in a wok or small frying pan, then remove the pan from the heat and stir in the chilies, fish sauce, lime juice, shallots, ground rice and chopped scallions. Put the pork chops and mushrooms on a large serving plate and spoon over the sauce. Garnish with the cilantro leaves and shredded scallions.
To make your ground rice: in a dry non-stick fry pan toast dry uncooked rice until it is a light brown, then using either a mortar and pestle or a spice grinder, grind until it is a powder.