Preheat oven to 200°C (400°F), using conventional heat rather than fan-assisted to prevent drying the meat.
Prepare the pork fillets: wash, pat completely dry, and trim any excess fat.
Heat a light coating of oil in a roasting pan over high heat until very hot.
Place the pork in the hot pan and sear on all sides until browned, about 3 minutes per side.
Season the seared pork with salt and pepper.
Pour roughly 1/8 liter (about 1/2 cup) of water into the pan around the pork.
Transfer the roasting pan to the preheated oven and cook for 10-15 minutes until the pork reaches an internal temperature of 63°C (145°F).
Remove from the oven and allow the pork to cool in the pan for about 5 minutes.
Slice the pork into thin slices.
Layer the pork slices in a shallow bowl or deep plate, separating each layer with pan juices and light seasoning of salt and pepper, ensuring all slices are surrounded by liquid.
Refrigerate for at least 4 hours (8-10 hours preferred) before serving.