Melt Becel® Buttery Taste margarine in small saucepan over medium-high heat and cook garlic, stirring frequently, 1 minute. Stir in miso paste, maple syrup, vinegar and water. Bring to a boil over high heat. Reduce heat to low and simmer, stirring occasionally, about 15 minutes; let cool. Reserve ¼ cup (60 mL) miso-maple mixture; set aside.
Grill pork, turning occasionally, brushing with remaining miso-maple mixture, until pork is done, about 15 minutes; thinly slice.
Grill onion and bok choy until tender. Serve vegetables with pork, drizzled with reserved miso-maple mixture.