1. Cut the stems of the greens. Wash the greens well.
2. The best way to wash them for me is to fill my kitchen basin with water and then put the greens in it.
3. Clean it well and most often you would find a residue of mud on the surface of the basin.
4. Chop them coarsely and place them in a steamer. You can alternatively boil the greens if you wish.
5. Blend the greens into a puree along with the green chillies.
6. You can do it coarse or smooth as per your taste.
7. Now in a skillet, saute the grated onions, turmeric, ginger-garlic paste and coriander-cumin powder (if using) in Ghee (or oil).
8. Add the crumbled paneer and cook for 5 minutes until paneer is soft.
9. Add the greens puree.
10. Stir the mixture until everything comes together and the it comes to a boil.
11. You can thicken the mixture if watery with Makai Ka atta (Maize flour/corn flour) for that authentic touch, followed while making Sarson Ka sag.
12. Or else a little cornstarch should do it too.
13. If too thick, add little water to get your desired consistency.
14. Add salt. You can also add lemon juice.

Courtesy: http://chefinyou.com/