To make the sauce, preheat a large cast iron skillet over medium-high heat, about 5 minutes. Add shallots, fresh garlic cloves (not the black garlic), Thai chiles, and serrano chile. Cook, turning as needed, until charred all over (about 4 minutes for Thai chiles, 6 minutes for garlic, 8 minutes for the serrano chile, and 12 minutes for shallots). Transfer charred shallots, garlic, and chiles to blender.
Meanwhile, in a small heavy skillet over medium heat, stir coriander seeds and cumin seeds until toasted and aromatic, about 3 minutes. Add toasted seeds to blender.
Add sugar, vinegar, mustard, 1/3 cup lime juice, fish sauce, black garlic cloves, ginger, and salt to blender. Blend until mixture is completely smooth, scraping sides as needed. Add herbs and squid ink (if using) and blend again until completely smooth. Check seasoning and add more salt and lime juice, if necessary. Let cool, transfer to a shatterproof container and store in the refrigerator or cooler for up to five days.
To make the pork, build a two-zone fire in a charcoal or gas grill, or fire ring. For a gas grill set half the burners to medium-high heat and the other half to low. For a charcoal grill or fire ring, bank the hottest coals up and to one side of the cooking area.
Season the pork chops with salt and pepper on both slides, Cook for three minutes on one side, brush the top with sauce, and turn over. Cook for three minutes more. Brush the top with sauce and flip pork chop. Cook three minutes more, If the sauce begins to burn or flare-ups occur, move the pork to the cool side of the grill. Repeat until the pork chops are burnished a deep golden brown and the internal temperature reads 125 degrees on an instant read thermometer, Transfer pork chops to a cutting board. Let rest 10 minutes and then cut into ¼-inch slices against the grain.