Peel and wash green peas. Peel the potatoes, wash and cut into small pieces(if there are boiled potatoes then you can cut and put them).
Wash the tomatoes and cut into big pieces, cut off the stems of the green chillies then wash them. Peel and wash ginger. Make a coarse paste of the peas and keep in a bowl. Grind the tomatoes and green chillies to a fine paste.
Cut ginger into small pieces.
Pour oil in a frying pan(kadhai) and heat, put the pieces of poatato and fry till they turn brown. Then keep them on a plate.
In the leftover oil in the pan, put Heeng and Jeera. After Jeera is roasted add coriander powder, grated ginger, tomato-chilli paste and fry till spices seem granular. Once spices are fried put the pea paste and stir fry for 3-4 minutes with a spoon. Put the fried potatoes then add water according to how thick or thin you want the Nimona. Add red chillies and salt, after it comes to boil cook for another 7-8 minutes. Turn off the gas and mix garam masala to the curry.
Matar Nimona is ready, take it out in a bowl then garnish with green coriander and 1 tsp Ghee.
Serve hot Matar Nimona with parantha, chapati or rice.