Take cashews soaked in water, drain, and set soaking water aside. Place cashews in a blender and grind them into a fairly smooth paste. Add a little water if needed to make cashews into a paste.
Steam mixed vegetables until tender.
Place onion, garlic, ginger, chilies, and poppy seeds (if using) in a food processor. Process into a coarse paste or mince them. Add paste to nonstick, heavy steel or cast-iron pan and sauté until the mixture becomes fragrant or until it just begins to brown a bit. Add the turmeric, garam masala, and cardamon and stir.
Then add tomatoes and cook, stirring, until tomatoes break down, approximately 3 minutes. Add soy yogurt and stir, letting the paste cook for another 2 to 3 minutes. Add salt, if using.
Add cooked vegetables, raisins, and cashew paste, mixing well. When the gravy comes to a boil, turn down the heat and simmer on a low flame for another 5 minutes for the flavors to incorporate. Garnish with cilantro.