1 Grate unpeeled ginger on large holes of a grater. Gather grated ginger, and squeeze juice into a small bowl. Measure out 1 Tbsp (15 mL) ginger juice. Discard grated pulp.
2 In a medium bowl, whisk together measured ginger juice, pineapple juice, soy sauce, brown sugar, canola oil and salt. Place half of the mixture in an airtight container and refrigerate; reserve for sauce.
3 Place chicken breasts in a resealable plastic bag; add remaining marinade, and squeeze out excess air. Marinate in refrigerator overnight; turn as needed to evenly coat.
4 To make sauce, remove reserved marinade from refrigerator, and boil in a small saucepan over high heat until slightly thickened, about 3 to 5 minutes; set aside.
5 Preheat grill to medium. Clean it with a stiff brush, then rub with canola oil. Remove breasts from marinade, and shake off excess. Discard marinade.
6 Grill until cooked through, about 4 minutes per side or until internal temperature registers 160 F( 70 C) on an instant-read thermometer inserted into thickest part of breast.
7 Spoon sauce over breasts, and sprinkle with green onions; serve hot or at room temperature.

Source: canolainfo.org