Heat 1 tsp of the oil in a cast-iron or nonstick skillet and add the lotus seeds. Stir-fry them, stirring constantly, until they turn golden-brown and crisp. You don't want them to blacken.
Put the lotus seeds in a bowl and set aside.
Make a paste with the cashews and 1 cup of water and set aside.
Heat the remaining oil in a skillet (if you used a cast-iron one to roast the lotus seeds, replace it with a nonstick or stainless steel one for the rest of the recipe. You're using tomato in the recipe and acidic ingredients don't react happily to cast iron).
Add the onion and saute over medium heat until it turns transparent, about 5 minutes.
Add the ginger and garlic and saute for a few seconds.
Add the powdered spices and saute another 30 seconds.
Add the tomato puree and mix thoroughly. Cook, stirring frequently, until the tomatoes darken and the oil begins to express itself.
Add the lotus seeds, the frozen green peas, and the kasoori methi. Give it all a good stir and add a cup of water.
Once the curry comes to a boil, add the cashew paste and salt to taste. If the curry is too thick, add some water. I like my curry rather thick-- perfect to scoop up with an oven-fresh naan.
Spritz in a few drops of lemon juice for some added complexity. Garnish with chopped coriander.