Preheat the oven at 250° C. Slit and flatten chicken breasts with the handle of a knife. Place them on a plate and sprinkle some salt. Apply ginger-garlic paste and lemon juice on both the sides.

Heat butter and 1 tsp oil in a non stick pan. Add ginger, garlic and half the green chillies and sauté for a minute. Add almonds, pistachios and minced mutton and sauté for a minute. Add red chilli powder, ½ tsp garam masala powder, ½ tsp kasoori methi powder, salt and sauté for 1-2 minutes.

Transfer the mince mixture into bowl. Finely chop the mint leaves and add.Spread the mince mixture on the chicken breasts and roll them in the shape of a bitter gourd (karela). Heat 2 tbsps oil in a non stick pan. Add gram flour and sauté on a low heat for 2 minutes. 

Roughly chop coriander leaves, mint leaves and add along with the remaining green chillies. Switch off the heat and stir for a minute. Transfer this mixture into a mixer jar. Add hung yogurt, mustard oil and grind into a paste.