Heat 2 tablespoons of oil in a pan or skillet and add the chopped onions.
Add salt and saute the onions in medium heat until the onions are almost caramelized or browned really well, which will take around 15 to 20 minutes. Make sure to stir the onions in between, especially after start turning brown so as to avoid the onions getting burnt at the bottom of the pan. Once the onions are caramelized or browned, keep this aside.
Once the pressure cooker is cooled enough, open the cooker and see if the peas is cooked really well. You might think the peas is a bit overcooked, but try it that way as it will make the gravy more delicious. Stir the cooked peas really well.
In a medium or large sized pan, heat the remaining one tablespoon of oil and add the cumin seeds.
When the cumin seeds are lightly browned, add the ginger garlic paste and green chilies, stir fry in low heat for about a minute.
Add the cooked peas mixture to the pan and stir the contents well.
Add the caramelized onions also to the pan containing the peas and mix everything well. You can check if there is enough salt, and if you need more salt, you may add a little more based on your preference.
Add the spices - turmeric powder, red chili powder, coriander powder and garam masala powder, mix everything well and bring the mixture to a boil.
Once the mixture starts boiling, add the paneer cubes to the mixture, gently stir the contents, cover and cook for about 5 to 6 minutes or until the paneer is soft. Make sure not to overcook as the peas is already cooked and we don't want the paneer cubes to break down and become crumbly. So just cook a few minutes until the paneer is cooked and tender. Gently stir in between using a good quality steel spatula which will help with mixing gently without breaking the paneer.
Once the paneer is also cooked, gently mix in the contents again and the matar paneer curry is ready to be served! Enjoy the delicious matar paneer or peas paneer curry with rice, pulao, chapathi, roti or poori as you wish.