In a saucepan, heat the stock and add the whole spices and turmeric to it. When the stock comes to a boil, add the rice.
When most of the liquid is absorbed by the rice, turn the heat to low, cover tightly with a lid, and let the rice cook on low heat for 15 minutes. Turn off the heat.
Heat 1 tablespoon of the oil in another, larger pot with a tight-fitting lid.
Add the sliced onions and saute over medium heat until the onions turn golden-brown.
Add the ginger and garlic and saute another minute.
Add the mushrooms and tomatoes and cook until the tomatoes have broken down completely.
Add the toasted spices and stir in.
Now add coconut milk and peas and salt. Cook another 5 minutes over low heat.
Now layer the cooked rice on top of the sauce in an even layer. Cover with the lid and cook for about 15 minutes on very low heat.
Heat 1 teaspoon oil in a saucepan. Add the raisins and nuts and stir until the cashew nuts are lightly browned.
Garnish the biryani with the nuts and raisins and cilantro. You can also garnish with crisply fried onions.
Enjoy piping hot!