Smoky grilled lamb skewers with cumin and chili are an iconic Chinese street food. A high protein, carnivore-friendly family favorite with bold, fresh spices.
In a large bowl, add the lamb cubes, onion wedges, and bell pepper pieces. Toss with vegetable oil to coat all surfaces evenly.
Sprinkle ground cumin, chili flakes, kosher salt, black pepper, and sugar over the lamb mixture. Mix thoroughly so the seasoning adheres well to all sides.
Thread the seasoned lamb, onion, and bell pepper pieces alternately onto soaked bamboo skewers, leaving a little space between each piece for even cooking.
Preheat grill to high heat (450–500°F). Once the grill is hot, arrange skewers directly over the grates. Grill for 2–3 minutes on each side, turning frequently for even searing and grill marks.
Reduce grill heat to medium and continue to cook for another 6–8 minutes, turning occasionally, until lamb is just cooked through but still juicy. Remove from grill, rest for 3 minutes, and serve hot.