Combine all marinade Ingredients in a bowl. Add chicken and mix it well and refrigerate for at least 2-4 hours, tossing it from time to time to ensure it marinates properly.
Preheat charcoal or gas grill to medium-high heat. Thread chicken cubes onto the skewer and grill, turning frequently until the chicken is browned and cooked.
Remove the skewers from the grill and allow the chicken meat to cool a little before removing it from the skewers.
In another bowl, combine coked grilled chicken, red onion, cilantro, green garlic green chillies, lemon juice, ginger, cumin, cayenne pepper, turmeric, Szechuan pepper.
Heat mustard oil in a small skillet when the oil is hot but smoky. Add fenugreek seeds and dried chillies and fry until fenugreek turn reddish brown and fragment.
Add garlic. Cook for a few seconds and immediately pour the entire contents of the pan onto the chicken and toss well.
Cover the bowl and allow it to season and develop for at least 15 minutes.
Put it in a serving dish and serve.