Clean and trim spinach leaves. Wash them thoroughly under cold water.
Boil water in a pan. Add spinach rinsed spinach leaves to it and let it boil for 2-3 minutes.
After the boiling time is over, use a slotting spoon to remove the spinach leaves from water and immediately plunge it into a large bowl full of ice water.
This will stop the cooking process. Remove spinach from water and tightly squeeze out all of the excess water from the spinach leaves. Form a small ball and store it in a Ziploc bag. Freeze for future use.
Transfer the blanched spinach to a blender and blend until smooth. Blanched spinach is ready. Set it aside.
In a large mixing bowl, combine yogurt (thick hung curd) with red chili powder, coriander powder, kasoori methi, garam masala, salt, and lemon juice. Whisk until combined.
Place the chicken cubes in a deep dish. Pour the marinade over the chicken cubes.
Rub the marinade all over the chicken cubes making sure it is well coated. Cover and refrigerate for 3-4 hours.
COOK THE MARINATED CHICKEN
After the resting time is over, heat ghee in a heavy-bottomed pan. Add the marinated chicken to the pan.
Continue cooking on medium-high heat, frequently stirring until the chicken is cooked. Remove from heat, and set aside.
ASSEMBLING SPINACH AND CHICKEN TOGETHER
Heat mustard oil in a pan. Mustard oil has a very strong flavor. Therefore, to get rid of that pungent flavor, cook mustard oil to its smoking point and take it off the flame. Let it cool.
When ready to make the masala – slightly warm the mustard oil and add whole spices and cumin seeds to the pan.
As the seeds start to crackle, add onion and ginger-garlic paste. Mix to combine. Sauté for 3-4 minutes until the oil starts to separate.
Stir in the tomato puree. Mix to combine.
Stir in all the spices – coriander powder, chili powder, kasoori methi, garam masala, and salt. Mix until combined.
Cook the tomatoes for another 3-4 minutes or until the oil separates.
Pour in the blanched spinach puree. Stir to combine.
Add chicken pieces to the blanched spinach. Cook for another 3-4 minutes on medium-low heat, stirring occasionally.
Finally, add the cream. Give it a gentle stir and take it off the flame.
Serve hot with warm rotis, naan or white rice.