Wipe the ribs dry with a kitchen towel.
Heat the sesame seed oil in a shallow pan wide enough to accommodate the ribs in a single layer.
Drop the ribs in the hot oil making sure they don’t overlap.
Cook over high heat to sear the ribs. Give them quarter turns for even browning.
Sprinkle the grated ginger over the browned ribs.
Pour in the soy sauce, black vinegar and mirin. Swirl the pan a few times to mix the liquids together. Bring to the boil and cook uncovered for about five minutes, turning the ribs a few times.
Pour the orange juice over the ribs and sprinkle in about a teaspoonful of salt. Bring to the boil, lower the heat, cover the pan tightly and cook the ribs for about an hour or until the meat is tender.
Taste the sauce. If it needs more salt, add some. You may also add some sugar if you prefer a sweeter sauce. If you used commercial orange juice, you will likely need to add some sugar.
Turn up the heat and continue cooking the ribs until the sauce is sticky and almost dry. During the last few minutes, turn the ribs around to caramelize as much of the surface as possible.
Arrange the ribs on a serving plate.
Drizzle whatever sauce is left in the pan over them.
Garnish with mandarin orange segments and sliced scallions.
Serve your Mandarin pork ribs while hot.