Add the garlic, ginger,green chilli paste and tomatoes and simmer till the tomatoes are cooked. Mash lightly using a potato masher and add 1 tbsp water.
Add the green peas,potatoes, salt,chilli powder, garam masala and and cook for 3 to 4 minutes.
Add 1 cup of water and allow it to come to a boil.
Mash 2 to 3 pieces of potatoes in the pan to thicken the gravy. Simmer till the gravy thickens.
Garnish with the coriander and serve hot with rotis or parathas.