Make the marinade by combining the yogurt, oil, ginger, garlic, salt, lime juice, tandoori paste and garam masala in a large non-reactive bowl and mixing the ingredients together well.
Add the onion chunks and the chicken, cover the mixture with plastic wrap and marinate the chicken overnight in the refrigerator.
Prepare your grill for direct medium heat. Thread the chicken pieces and marinated onions onto the skewers.
Grill the kebabs for 4 to 6 minutes, turning them 2 or 3 times. Don't overcook the chicken or it will have a mealy texture.
Remove the kebabs from the grill.
Drizzle them with a little oil, season them with salt, squeeze some fresh lime juice over each skewer and serve immediately.
