Heat a pan/utensil and add ghee. When hot, saute the cashew nuts, raisins and onions separately, till they turn golden brown. Drain and keep aside.
In the remaining ghee, lightly toast the rice. Add boiled water and salt. Cover with a lid and cook on high flame, for 3 minutes.
Transfer the pan/utensil onto a griddle and cook, for another few minutes (our aim here is to avoid direct heat). Stir the rice lightly with a spoon, cover and cook for another 5 minutes. Switch off the heat.
In another pan, heat oil. When the oil is hot, add onion along with 1/4 tsp salt and saute for a while.
Cover with a lid and cook on low heat. Stir in between, to avoid sticking to the bottom of the pan.
Once the onions turn pink, add turmeric, chilli paste, ginger garlic paste, sliced tomatoes and lime juice. Mix well, cover and cook on low heat.
Once all the ingredients are well blended, add cleaned and washed mutton, with salt and stir well. There is no need to add water. Cook on low heat with the lid on, till the mutton is 3/4 cooked.
Take off the lid and let it cook, till there is no more liquid.
Add garam masala powder, coriander leaves and take off the heat.
If you want to have some colour to the biryani, take a bowl of cooked rice and divide into two. Add yellow colour into one part and red colour into the other. Mix well and keep aside.
Take a utensil and spread a layer of rice topped with some lamb. Sprinkle a pinch of garam masala powder. Put another layer of rice, followed by mutton.
Continue the process and finish off with a top layer of rice.
Add the coloured rice, if using. Sprinkle garam masala powder and rose water. Cover the utensil with a lid and seal the edges with atta (dough made of wheat flour). Keep it atop a griddle and cook on low heat for 30 minutes.
Those opting for baking, can take a deep dish and layer the rice and mutton as mentioned above. Cover with an aluminium foil and place on a preheated oven of 180 degree C and bake for 30 minutes.
Arrange in a dish and garnish with the fried cashew nuts, raisins, onions and chopped leaves.
Your Malabar mutton/lamb biryani is ready to be served.
You can eat it plain or serve with raita and pickle.