Using a sharp knife, cut scallions or green onions lengthwise into thin slivers. Toss with cabbage, bok choy, or gai choi and cashews; set aside. Stir together vinegar and sugar until sugar dissolves; set aside.
Cut tenderloins crosswise into 1-inch-thick slices; place between 2 sheets of plastic wrap and pound gently with the flat side of a mallet to 1/2-inch thickness. Spread medallions lightly with half of the green curry paste.
Place medallions on the lightly oiled rack of the grill directly over medium heat. Grill for 3 minutes on each side or until an instant-read thermometer inserted in centers reads 170 degrees F and juices run clear. Set aside; keep warm.
Stir together remaining green curry paste and wine in a small skillet. Cook, uncovered, over medium-high heat for 1 to 2 minutes or until liquid is nearly gone, stirring often. Carefully add coconut milk; bring to boiling. Reduce heat and cook, uncovered, for 1 to 2 minutes or until thickened to a sauce.
To serve, toss scallion slaw with vinegar mixture and arrange on individual plates. Arrange warm turkey medallions and drizzle with sauce. Makes 4 servings.