Chop and remove the flower ends of spring onions and chop the remaining stalk into small bite size pieces
Meanwhile in a small pan add few drops of oil.Add all the ingredients mentioned under masala except coconut and sesame.Roast them in medium low flame till red chillies becomes crisp and dal turns golden color.Add coconut to that and just saute it , may be for 1 min.Transfer all the ingredients to a mixer jar.
Next,dry roast sesame seeds in the same pan till it turns golden. Add it to the mixer jar containing other roasted masala ingredients. Once its little cooled , add little water and make a very smooth paste.
Heat 1 tbsp oil and stir fry chopped spring onions and tomatoes for 3-5 minutes adding little turmeric.
To the sauted veggies , add ground masala , jaggery , salt and tamarind . Add around 1/2 cup of water. Boil the gravy on sim till it thickens .
Season with mustard,hing and curry leaves.Switch off .
Serve Spring onion gojju hot / warm with plain Rice / roti / dosa / Idli
Notes
You have to roast sesame seeds very well. if its raw this dish will turn flop.
Basically this dish will be tangy ,sweet n spicy. So to get the authentic taste add more jaggery ,tamarind n chilli. But you can vary it depending on your pref.
You can substitute spring onion with raw mango / pineapple /bitter gourd/ dry raisins/ ladies finger/ Capsicum / orange peels.