Preheat the oven to 275 degrees F.
For the pork roast: Sprinkle the pork with salt and pepper on all sides. Preheat a large skillet over medium-high heat and coat with the oil. Sear the pork on all sides until golden brown, about 2 minutes per side. Set aside while you make the herb rub.
For the herb rub: In a food processor, add the coriander, fennel, chile flakes, salt, garlic, bay leaves, lemon zest, orange zest and rosemary. Pulse until a smooth paste is formed. Add the oregano, parsley and thyme. Pulse until smooth. Remove half of the paste and rub it all over the seared pork roast.
For the salt crust: Add the egg whites to the food processor along with the remaining paste. Process until thoroughly combined. Transfer this mixture to a large mixing bowl with the 10 cups of salt in it. Fold to combine and to coat the salt with the egg whites.
Lay down a bed of some of the salt mixture on a baking sheet and put the pork on top. Cover with the rest of the salt mixture, encasing the pork completely.
Roast until the pork reaches an internal temperature of 130 degrees F, 1 hour 45 minutes to 2 hours. The salt will become hard, so you may need to press firmly when inserting the thermometer into the roast. Avoid hitting the bones, or you could get an incorrect reading.
Meanwhile, for the smashed potatoes: Place the potatoes in a large pot and cover with salted cold water. The potatoes will soak up that salt like pasta and it will make a big difference in flavor. Cover the pot, bring to a boil, and cook until the potatoes are fork-tender, 20 to 30 minutes. Drain the potatoes and return them to the pot, allowing them to dry. Melt the butter with the half-and-half in a small saucepot over low heat. Add the potatoes along with the cream cheese, and season with salt and pepper. Smash with a potato masher and set aside, keeping warm until ready to serve. Right before serving, fold in the parsley and thyme.
Remove the pork from the oven and let it rest in the salt crust for about 20 minutes. The pork will continue to cook as it rests because it is encased in the salt. Once fully rested, break open and brush off the salt crust. Slice the roast and serve.