In small, dry frying pan, heat cumin seeds over medium heat until fragrant or until they start to turn golden, about 2 minutes. Remove to cool then place into electric grinder, or mortar and pestle, and grind until fine. Place into mixing bowl and mix together well with rest of spices, garlic, pepper and salt.
In another mixing bowl, mix lamb and canola oil until well coated. Add spice mixture and mix well to coat. Cover with plastic wrap and refrigerate for at least 6 hours or overnight. Alternatively, marinate in large, heavy, resealable plastic bag and refrigerate.
Skewer four to five pieces of lamb on each skewer. Heat prepared grill or barbecue until medium high to high heat.
Brush small amount of canola oil over each skewer and grill, turning frequently, about 6 to 8 minutes, or until desired doneness.
9 bamboo skewers soaked in water overnight (canola oil for brushing).