Marinate the chicken for 15-20 minutes by mixing all the ingredients for the chicken marinade.
Dry roast the ingredients for the karahi masala on low flame for 2-3 minutes until fragrant.
Cool and grind them into a powder.
Heat mustard oil in a kadai, add the whole spices, and wait for the cumin to splutter.
Add onions and sauté for a minute, followed by ginger garlic paste, turmeric, chili powder, coriander powder, cumin powder, and 2 tbsp of karahi masala.
Cook for another 1-2 minutes until the raw smell disappears.
Add salt, julienned ginger, and chopped garlic, sautéing for a minute on high heat.
Then, add tomato puree and cook for 2 minutes until the oil separates.
Add the marinated chicken and stir fry for 2-3 minutes.
Add ½-¾ cup water, cover, and cook on low heat for 25 minutes.
In a separate pan, heat ghee and stir-fry whole red chilies, sambar onions, and capsicum on high heat for 2-3 minutes until blistered.
Once the chicken has cooked, add the roasted vegetables and mix well.
Add garam masala, kasuri methi, and butter, cooking for another 5 minutes.
Stir in chopped coriander and let the dish sit for 10 minutes before serving.