Heat oil & butter in a wide pan. Once oil it’s hot enough, and add the whole spices.
Once it splutters, add in finely chopped ginger & garlic. Sauté for a minute until light golden. Now, add the marinated chicken & fry on high heat for 1 min and then flip the chicken pieces.
Continue to fry for 2 more mins on high turning the pieces a few times.
Add the remaining marinade and continue to fry on both sides for another 5 mins on medium heat until evenly browned.
Now reduce to low heat, add the yogurt, 1 tsp crushed Pepper, slit green chillies & garam masala. Add 1/2 cup water and mix everything well.
Cover & cook on low heat for 15 mins, flipping and stirring after 10 mins. Make sure to scrape the bottom so that it doesn't stick & burn. Cook till the liquid has nearly dried and the chicken is tender & soft.
Increase the heat and fry for another 5 mins uncovered till the chicken pieces are browned & fried well.
Garnish with finely chopped coriander leaves and serve hot.