Rinse the liver and wipe dry with paper towels. Optionally, for easier slicing, freeze the pork liver for an hour or so or until partially firm.
Slice the liver into 1/4-inch slices.
In a mixing bowl, stir together the ginger, garlic, soy sauce, lime or lemon juice, oyster sauce, pepper and sugar.
Add the liver to the marinade and mix well.
Cover the bowl and marinate the liver slices in the fridge for at least two hours.
Drain the liver slices. Reserve the marinade.
Heat the cooking oil and sesame seed oil in a wok or frying pan. Swirl to coat as much of the cooking surface with oil.
When the oil starts to smoke, spread the liver slices on the cooking surface. Try to have all pieces in a single layer.
Cook without disturbing for about two minutes then flip them over. Cook for another minute.
Pour in the marinade and add half of the spring onions to the liver. Stir fry for a minute or just until the liver slices have soaked up the marinade.
Turn off the heat. Add the remaining spring onions and toss.