Bring a pan to medium high heat and scatter all the spices mentioned under the ingredients for garam masala. Keep tossing and turning for about 30 seconds and then, take the pan off the heat. Allow the spices to cool down and then, grind it to powder.
In a big mixing bowl, pour the yogurt along the oil, salt and the prepared garam masala powder. Give it a whisk and then, drop the chicken tenders. Give it a mix to coat the chicken tenders evenly. Cover the bowl and allow it to marinate for a minimum of 4 hours. If you can keep it overnight in the refrigerator, the flavor will definitely get better.
Place a grill pan on medium high heat and brush some oil on the pan. Once the pan is hot, layer the chicken tenders without overcrowding the pan. Grill it in batches, if required, because you definitely want those grill marks. Cook it for 4 minutes and then using a tong, flip the chicken tenders and cook for another 3 minutes.
Once done, take it off the grill pan on a serving dish and allow it to rest for 2 minutes. Then, serve with your choice of dipping sauce. Cool yogurt mixed with some fresh finely chopped herbs, salt and a pinch of sugar works as a great dipping sauce for this dish.