Rinse the sarson ka saag well, in cold running water, to get rid of every last bit of grit. Chop the saag roughly, include the tender stalk, and discard tough stalk, yellowing or spotted leaves.
Let the washed greens stand for 5-10 mins in a large colander to drain. Meanwhile prepare the other ingredients as required.
Heat the pan and add a tablespoon of oil. Saute the onions till translucent.
Add the sliced washed greens and saute. Cover the dish and let the greens cook for 7-10 minutes, stirring well and frequently.
The saag (greens) will reduce to about a fourth of its original volume. Transfer to another dish to cool.
Puree in a food processor or mixie without adding water or using very minimum water. Heat the pan again, add 2 teaspoons of oil.
Burst the methi seeds in the oil and then add jeera. Scald the chillies in the hot oil. ( I usually let them discolour so that they are easy to identify and nobody bites into them by mistake)
Add the garlic and saute, and then add ginger. Add turmeric and chilli powder. Sauté for one minute. I prefer Kashmiri chilli powder as it gives colour and flavour without being too spicy.
Add and saute the capsicum. Capsicum is not part of the traditional recipe, but I like to add it for the contrasting texture to the soft saag.
Add the tomatoes, sauté for a minute.
Add the pureed saag.
Sauté, stirring frequently, for 5 minutes on a low flame. Add salt to taste. Cover for 1 minute. The saag may catch at the bottom and scald if covered for too long .
Transfer to a serving dish. Garnish with cream (if desired) and serve hot with roti and white butter.