Cut the chicken into medium cube size pieces .For the marinating sauce, blend all the above mentioned ingredients (yogurt, salt, cumin/coriander powder, ginger/garlic paste, turmeric powder , chili paste, fenugreek leaves and Timur ) except for lime juice, black pepper and mustard oil.Pour the marinating sauce over the meat and mix it well. Marinate it for at least 4 hours ( I let it sit for overnight if i have time and patience :D )Add the black pepper, lime juice and mustard oil when the meat is ready to be grilled.If you are using a wooden skewers , soak it in water for 20 min before using it. This will prevent the skewers from burning while put on grill. I prefer using metal skewers because its easy to use and don't have to worry about it getting burned.Oil your metal skewer and pierce the chicken cubes into the skewers ( shown in above picture), do not tightly pack the chicken cubes. It needs to be cooked evenly.Grill the skewers over medium heat for 5-8 min basting with oil while turning sides.When ready garnish with some cilantro, lemon and onions.