Pour the stock into a hot wok. When it begins to boil, add the pork meat and liver and cook, stirring, for 2 minutes, or until the meat is cooked.Transfer the mixture to a mixing bowl and allow to cool for 2 minutes. Add the mint, coriander, spring onion, chilli, rice powder, padek or mam nem and lime juice. Mix together well, then transfer to a serving platter. Garnish with some extra chilli slices.
Serve with the raw vegetables and sticky rice.
Note: To make pork stock, wash 500g pork bones under cold water, then place in a large pot. Peel a 2cm piece of fresh ginger and 4 garlic cloves, then cut each in half and add to the pot. Bash 1 lemongrass stem and 2 spring onions (scallions) with the back of a cleaver or mallet, then add them to the pot. Pour in 2 litres water and bring to the boil. Skim off the impurities from the stock, then reduce the heat and simmer for 2 hours, skimming constantly. Pour the stock through a net strainer into another saucepan and allow to cool. Once cooled, portion into smaller amounts and refrigerate or freeze until required. The stock will last in the fridge for 3 days, or in the freezer for 3 months.