Combine yogurt, garlic, onion, ginger, lemon juice, curry powder, chili powder and salt in large sealable freezer bag. Pierce roast all over with fork. Place in bag with marinade; seal bag, squeezing gently to massage marinade into beef. Refrigerate for 12 to 24 hours. Discard marinade.

Place drip pan containing ½ inch (1 cm) water under grill. Preheat barbecue to medium-high (400°F/200°C). To Cook with Rotisserie: Insert spit rod lengthwise through centre of roast; secure with holding forks and place roast over drip pan. To Cook without Rotisserie: Place roast on grill over drip pan that is moved to one side; turn off burner under just the roast.

Insert meat thermometer into middle of roast, avoiding spit rod (if using). Cook at constant heat, in closed barbecue, until thermometer reads 145°F (63°C) for medium-rare, about 1-½ hours. Remove roast to cutting board; tent with foil for 10 to 15 minutes. Carve into thin slices across the grain. Serve with Cumin-Scented Dressing.

Cumin-Scented Dressing

Combine 3/4 cup (175 mL) EACH mayonnaise and ranch dressing, and 1-1/2 tsp (7 mL) ground cumin. Refrigerate 1 to 2 hours for flavours to develop. Makes 1-1/2 cups (375 mL).