In a mortar add the white peppercorns. Pound until finely ground. Add coriander roots and garlic and pound until everything is mashed together well. Set aside.
In a skillet heat the oil over medium heat. Add the garlic-cilantro-peppercorn mass and fry until fragrant. Add the pork and fry, stirring often, until the pork is cooked through and mixed with the paste.
Add fishsauce and palm sugar. Stir to help the pork absorb the seasonings. Add the peanuts.
Taste the mixture. It should be savoury with a hint of sweet. If necessary adjust the seasonings.
Peel and core the pineapple. Slice the pineapple into 2cm thick slices. Cut the slices into bite-sized pieces.
To assemble the dish, lay the pineapple pieces on a serving dish. Top the pieces with the pork mixture. Garnish the top with a coriander leaf and a sliver of the prik chee fah.