Make a fine paste of green chillies, garam masala, ginger, garlic, cashew nuts & coconut.
In a pan heat 3 tbsp butter or oil and add half of the onions and fry until golden brown.
Add the paste to the onions and stir for about 5 minutes.
Add the prawns and 1/2 tsp salt. Mix well so that all the prawns are coated with the cooked masala and cook on a low flame for 5 minutes. Remove from heat and set aside.
In a separate pan heat 2 tbsp of butter or oil and fry the bayleaves and add the remaining onions and fry until the onions are golden brown.
Add the rice and stir fry for about 10 minutes. Add the peas, 1/2 tsp salt and 2 cups of water.
Cover and cook till the rice is almost done on a low flame. Mix the prawns and rice together.
Simmer, lastly add lemon juice and garnish the biryani with fried cashewnuts.