Remove and discard the bones from the fermented fish. Dice the flesh and place in a mixing bowl with the pork, sugar, pepper and garlic. Mix together well, then stir in the whole egg. Spoon the mixture into a glass or ceramic bowl and sprinkle the shallots over the top. Cover the bowl with plastic wrap.
Half-fill a steamer, wok or large saucepan with water and bring to a rapid boil over high heat. Set the bowl in the steamer, then cover and steam over high heat for 30 minutes. Remove the lid and plastic wrap. Pierce the surface of the terrine 5 times with a bamboo skewer, then pour the beaten egg yolks over the terrine. Steam until the yolks are set, 5 minutes longer. Remove from the steamer and garnish with coriander and chiles. Serve warm with steamed jasmine rice.