Firstly, take 4 cups of spinach or palak, remove the stems, wash the spinach thoroughly. I always soak spinach in ample water for 10-15 minutes along with 2 tsp salt and 1/2 tsp turmeric powder to get rid of any impurities or pesticides. This process is optional. You may directly rinse the spinach thoroughly with water.
Further, take 4 green chilies, deseed them, take 1-inch ginger, 4 cloves garlic, and 1 onion and chop them finely.
Heat 1 tsp oil in a pan, saute chopped onion-ginger, and garlic into it.
Add chopped spinach to it. and cook for 2 minutes. Spinach will leave the water and will be cooked in its own water. In this hara bhara kabab I prefer quick cooking of spinach in its own water as I do not have to throw the nutrient-rich water of spinach after boiling it, alternatively, you can blanch the spinach in boiling water for 2 minutes, take the spinach out, and put it in ice-cold water for some time.
Squeeze out whatever little water the spinach has, add 6 cashews to it and keep this spinach mixture in the freezer for some time, I always keep the blanched or cooked spinach or palak in the freezer to retain the green color. After some time, grind this mixture into a paste or puree.