Trim all the leafy greens and wash under running water. Place a deep non stick pan over medium heat and add 8 cups of water and bring it to a boil.
Add the leaves and blanch it in boiling hot water for 2-3 minutes. Drain in colander and refresh under cold water. Squeeze out the excess water, cool and puree. Transfer into a deep bowl.
Place a non stick shallow pan on medium heat and pour in 2 tablespoons oil. Add the cumin seeds, garlic and chillies and sauté.
Add salt and turmeric powder and stir. Add gram flour and continue to sauté for 1-2 minutes. Add the prepared puree and sauté, stirring continuously, until the mixture is dry and begins to leave the sides of the pan. Set aside to cool. Divide into 8 equal portions.
Take cow’s milk in a deep pan, and let it come to a boil. Take pan off the heat and add vinegar, once the milk curdles, strain it in a muslin, set the whey aside, do not discard.
Dip it in a bowl of ice water to cool the chenna.
Remove the muslin with chenna from the water and squeeze out excess water.
In another bowl mash the chenna along with salt and ⅛ teaspoon green cardamom powder. Divide into 8 equal portions and roll into balls.
Take a portion of the sautéed greens, flatten it on your palm and place a chenna ball in the center. Gather the edges and shape into a ball. Similarly prepare the remaining koftas.
Spread the cornstarch in a plate and rolls the stuffed koftas balls in it. Shake off the excess.
Heat sufficient oil in a kadai. Gently slide in the koftas. Cook for 2-3 minutes on low heat or till golden brown. Drain with a slotted spoon and place on an absorbent paper. Use as required.