Heat vegetable and sesame oil over medium-high heat in large non-stick skillet. Add steak and brown, about 2 minutes per side. Set aside. Combine sodium reduced stock and soy sauce, sherry, chili paste, onions, garlic and ginger root in 3½ to 6-quart (3.5 to 6 L) slow cooker. Add beef, turning pieces to coat in sauce.

Cook, covered, on Low for 8 to 10 hours or on High for 4 to 6 hours or until beef is tender.

Mix cornstarch with 2 tbsp (30 mL) water in small bowl. Add to slow cooker; cook, covered, on High for 10 minutes. Add bok choy; cook, covered, on High for 5 to 10 minutes or until tender-crisp and sauce is thickened.

Stove-Top Option: Brown meat in large oven-proof skillet or Dutch oven as in Step 1. Meanwhile, in bowl, combine 2½ cups (625 mL) beef stock, soy sauce, sherry, chili paste, onions, garlic and ginger root; pour over meat. Cook, covered in a 325°F (160°C) oven for 1¼ hours or until fork-tender. Add bok choy and cook 3 to 4 minutes. Remove from oven. Using slotted spoon, remove steak and bok choy to platter and keep warm. Over medium-high heat, whisk cornstarch mixture into pan. Cook, stirring constantly, for 2 minutes or until sauce is thickened.