Soak dry green peas in water overnight or for at least 4 to 5 hours prior to cooking.
After soaking, drain the water used for soaking and wash the peas very well, keep it aside.
Wash the button mushrooms in fresh water for 2 to 3 times (even if it you are buying washed ones).
Transfer the washed peas and mushrooms to a medium sized pan or pot, add water (no need to add salt now).
Add cardamom pods, cloves and bay leaves to the pot.
Bring the water to a boil, and when the water starts boiling, reduce the heat to very low, close the pot and cook for about 10 to 12 minutes or until the mushrooms and peas are cooked and soft enough. Switch off the stove and keep the pot aside.
Now let us make the gravy for the curry.
Cut the onion and tomatoes roughly and transfer to a food processor and grind them into a paste (without adding water). You don't have to make it so smooth, as little pieces of onions and tomatoes are fine in the gravy. I used cherry tomatoes, you can use cherry tomatoes or regular tomatoes.
Heat 2 tablespoons of oil in a pan and fry cumin seeds.
Transfer the onion tomato paste to the pan and roast the mixture in low to medium heat.
Add the ginger garlic paste and mix well.
Stir the mixture occasionally to avoid the gravy getting burnt at the bottom of the pan.
Cook the onion tomato mixture until it is cooked well and the mixture starts separating from the oil. This may take around 7 to 8 minutes.
Add all the spices and salt and mix well and cook for another 1 more minute. Now the gravy for the mushroom masala curry is ready, so let us add the mushrooms and peas to this gravy now.
Transfer the contents of the pot with the cooked mushroom, peas and water (yes we use the water used to cook the mushrooms to make the gravy) to the pan with the onion tomato mixture and mix everything well.
Cook in medium heat for about 2 minutes, stirring in between or until the mushrooms and peas are well blended with the gravy and spices.
Switch off the stove and keep the pan aside. Now let us make the seasoning (this is optional, but its good to add).
Heat 1 tablespoon of oil in a pan and add mustard seeds.
When the mustard seeds start to splutter, add the red chilies and fry for few seconds and the seasoning is ready.
Pour the seasoning over the prepared mushroom peas curry and gently mix the contents. Mushroom peas curry is ready to serve!