Prepare the pork: Preheat the oven to 375 degrees F. Pulse the herbs, garlic, lemon zest and potato chips in a food processor until coarsely ground. Transfer to a shallow dish.
Season the pork with salt and pepper. Heat the olive oil in a large skillet over high heat. Add the pork, fat-side down, and cook, turning, until browned on all sides, about 10 minutes; remove from the skillet. Brush the pork all over with the mustard, then roll in the chip mixture. Place on a rack in a roasting pan and roast until a thermometer inserted into the center of the roast registers about 150 degrees F, 50 to 60 minutes. Let sit 10 minutes before slicing into chops.
Meanwhile, make the sauce: Whisk the sour cream, mayonnaise, pesto, herbs and lemon juice in a bowl and season with salt and pepper. Top with the tomato. Serve the chops with the sauce.