To make this easy vegetarian curry recipe, start by peeling the potato and onions. Chop the potato, onion and tomato into large cubes / chunks.
Grind the 'masala paste ingredients' to a fine paste in a small mixer jar, using upto 1/4 cup water to get a smooth paste.
In a 4 litre + pressure cooker or pan, heat the oil. Add mustard and cumin seeds.
Once seeds splutter, add the chopped onion and the ground paste and saute for 3-4 minutes.
Add the chopped potato and tomatoes to this along with the salt.
Saute this mixture for 2-3 minutes. Add the shelled peas, if using.
Add 4 cups water and bring this to a boil. Close the cooker with the lid and the 'weight'. Allow 2 whistles and turn off the flame.
Allow cooker to cool for 10 minutes. Open cooker, remove the curry into the casserole and garnish with fresh coriander.