Special equipment: 12 bamboo skewers, soaked in water for 20 minutes
For the marinade: Place the beef cubes in a large mixing bowl. Add the vegetable oil, soy sauce, sea salt, chili flakes, coriander, cumin, ginger powder, nutmeg, paprika powder, pepper and garlic and mix well. Cover and refrigerate for at least 30 minutes or overnight for a better result.
Preheat the grill to medium-high heat.
Thread the beef onto the skewers and grill for 3 minutes per side. Baste the beef with the oil as it cooks and sprinkle with the dried chili flakes and cumin.
Serve with the lemon wedges.