The Khmer dipping sauce called tuk meric is made with just a few ingredients and has as its flavor base a generous amount of coarsely ground black pepper and freshly squeezed lime juice. Its tangy, peppery notes complement the meatiness of simply seared steak. A mortar and pestle or the bottom of a heavy skillet work best for coarsely grinding the peppercorns; you also could pulse them in a spice grinder, but their consistency will be slightly more uneven. If using flank or skirt steak, cut the meat into two or three pieces that fit comfortably in the skillet.