Place the chicken stock, mustard, pure maple syrup, wasabi paste and soy sauce in a sauce pan over high heat and bring to a boil.
Reduce the heat to medium and simmer reducing the sauce by half.
Place a tray of ice cubes in a bowl and fill with water.
While the sauce is reducing, place the water in a medium sauce pan fitted with a steamer basket over high heat. When the water is boiling, place the bok choy in the steamer and steam for about 2 minutes. Remove from steamer and place in the ice water bath to stop the bok choy from cooking further. After they are cool, drain completely and slice in half lengthwise.
Preheat the oven to warm (175°F).
After the bok choy and sauce are prepared, heat the sesame oil in a large non-stick skillet over high heat. When the oil is nearly smoking, place the scallops in the pan so they don’t touch.
Sear on the first side for about 3 minutes and turn. Cook for another 2 – 3 minutes, remove to a plate and place in the warm oven.
Place the bok choy in the hot pan and sear for about 1 minute on the cut side. Turn the bok choy over and add the sauce and cook for about 30 seconds.
Arrange scallops and bok choy on plate and top with sauce. Sprinkle black sesame seeds over the top and garnish with fresh cilantro.
