Make Yogurt Sauce: Add all of the ingredients for the yogurt sauce (yogurt, cumin, coriander, garlic powder, salt, and lemon juice) into a small bowl and mix well. Set aside.
Saute Onion and Garlic: Heat a small saute pan over medium heat and add olive oil. Add onion and garlic and turn the heat down to medium low. Saute for 4-5 minutes, stirring often, until onions are translucent and begin to caramelize.
Season Lamb: Add the spices for lamb into a small bowl (cumin, coriander, paprika, cinnamon, ginger, all spice, salt, and pepper) and mix well. Add ground lamb, panko bread crumbs, onion to a large bowl. Mix well so the breadcrumbs and onion are well mixed. Sprinkle half of the spice mixture and mix well with your hands. Add the rest of the spice mixture and mix well again.
Preheat Grill: Preheat the grill on high. Scrape down and clean grates.
Shape Koftas: With slightly damp hands, separate the lamb mixture into 6 evenly sized portions. Gently shape each into a log shape. Clean hands and then gently skewer each log with the metal skewer. (This is where a kitchen scale can be helpful by weighing the total mixture and dividing by 6) Grill: Place koftas on grill but not directly over the flame for indirect heat. Grill for 2 minutes and then turn slightly. Grill this side for another 2 minutes and slightly turn again. Repeat for all sides (about 4-5 turns) for a total of 8-10 minutes. Internal temperature of the lamb should read at least 158℉ when lamb comes off the grill as the lamb will finish cooking (carryover cooking) when removed and will raise temp up to 160℉.