In a pan, bring 1 ½ cups of water to a boil. Add the drained, soaked rice to it along with the bay leaves and enough salt to flavor the rice.
Bring the mixture back to a boil, cover with a tight lid, and let the rice steam on the lowest heat setting for 10 minutes. Turn off the heat and let the rice stand.
Heat the oil in a large, heavy-bottomed pan. Add the shahjeera or caraway seeds, cardamom pods, and cloves. When they begin to turn color, add the onions and bell peppers.
Saute the onions and the peppers until the onions start to brown.
Add the ginger and garlic paste along with the green chilies, mint and coriander leaves. Saute for 30 seconds.
Add the pumpkin puree and mix well. Cook the pumpkin puree, stirring frequently, about 5 minutes.
Add the cashew paste and lemon juice and mix thoroughly. Cook for another two to three minutes, stirring frequently.
Fluff the cooked rice with a fork and add i to the pumpkin mixture in the large pan.
Carefully, taking care not to break the grains of rice, stir them with the pumpkin mixture to coat evenly.
Sprinkle on the non-dairy milk mixed with saffron threads.
Cover the pot with a very tight lid and let the biryani steam on a very low heat setting for 15 minutes.
Turn off the heat and let it stand for another 10 minutes before opening.
Sprinkle on some candied or dry cranberries and sauteed pumpkin seeds, as well as the spring onions.
Serve hot.