Mustard oil could be replaced with Olive oil. Red chilli powder could be replaced with Kashmiri chilli powder which gives the same flavor and color but is less hot. Chicken should be tender preferably weighing no more than 750 grams. Greens can be adjusted to amount of chiken.
Wash the mustard greens (only the leaves) and bring to a boil in a deep pan with enough salted water till tender. Drain water and keep aside.
Marinate chicken pieces with 1tsp salt, 1tbsp turmeric powder,1 tbsp of ginger,1 tbsp of garlic paste, lemon juice and a 2tbsp mustard oil for about an hour.
Heat 1 cup oil in a heavy bottom deep pan or wok, add the bay leaves and crushed black cardomom in hot oil. Once bay leaves change color lower the heat and add the onions
Fry for 2-3 minutes till the onions becomes glossy. Then add the chopped tomatoes and keep stiring on low heat for 4-5 minutes till all the water from the tomatoes dries up.
Add chicken pieces and cook for another 5-6 minutes, then add the rest of the ginger and garlic paste and the 2 whole red chillies .After 2 minutes of stiring add Coriander and red chilli powder.
Stir for 2 minutes more and add the cooked greens and salt according to taste. Mix well on low heat and cover with a lid.
Keep cooking till the chicken in done occassionally uncovering and stiring on low heat. You may add 1/2 cup of water if it gets too dry at the bottom of the pan.
Once chicken in cooked take out in a bowl and garnish with sliced carrot and lemon, sliced green chillies and serve with steamed white rice.