Set up a charcoal grill or tandoor for moderate heat, or heat an oven grill (broiler) to medium.
Place 600 g ground lamb in a large mixing bowl with 1 tbsp ginger paste (Pisi Adrak), 1 tbsp garlic paste (Pisi Lehsun), 19.8 g green chilli, 3 g coriander leaf, 2 tbsp Garam Masala (I), 30.6 g lemon juice, 0.3 g seasoning, salt to taste, and the kebab spices. Add 2 tablespoons each of the 4 tbsp onion, 6 tbsp spring onion, 4 tbsp tomato, and 4 tbsp diced pepper, keeping the remainder of the vegetables aside. Work the meat thoroughly with damp hands until well combined.
Divide the meat into 16 equal portions and shape each into a ball. Thread and press the balls along metal skewers, flattening each portion into a 10 cm (4-inch) sausage shape while leaving 2.5 cm (1 inch) of space between kebabs. Press the reserved chopped onion, spring onion, tomato, and pepper firmly across the outside of each skewer to form an even vegetable crust.
Grill the skewers over moderate coals, in the tandoor, or under the oven grill for 5 to 6 minutes. Take them off the heat and suspend vertically over a tray for 2 to 3 minutes so excess juices drain off.
Transfer the skewers to a tray, baste all over with 28.2 g butter, and grill for an additional 2 to 3 minutes until cooked through and lightly charred.
Use minced chicken (preferably dark thigh meat) at 100% of the weight. Halve the browning and simmering time; add an extra tablespoon of ghee or oil as chicken is much leaner than lamb.
Use 80% of the weight, finely shredded and browned slowly with a pinch of asafoetida. Replicates the bulk and natural sweetness in gravies without allium.
Use 40% to 50% of the fresh tomato weight mixed with a splash of water. Imparts a deeper red colour, thicker sauce, and slightly sweeter cooked flavour.
Use 50% of the weight mixed with equal parts ground coriander and a pinch of ground cinnamon, ground cloves, and ground green cardamom. Sprinkle near the end for a warming finish.