- In a large freezer bag, combine dressing, balsamic vinegar, garlic, coriander seeds and hot pepper flakes. Add leg of lamb and seal bag. Shake bag to thoroughly coat lamb with marinade.
- Repeat several times during marinating time. Marinate in refrigerator for 4 hours. Preheat barbecue to medium heat. Remove lamb from freezer bag and drain well.
- Place lamb on oiled barbecue grill and cook, covered, for 20 minutes per side, or until meat is pink and internal temperature reaches 70°C (160°F).
- Remove from barbecue, cover with aluminum foil and let stand for 10 minutes. Garnish lamb with fresh coriander. Serve with grilled vegetables and couscous.
Variation: Replace the vinaigrette with Dijon mustard and the balsamic vinegar with cider vinegar.