Soak all the rice, lentils and broken wheat overnight or for at least 3-4 hours in water. After soaking, drain the excess water and keep aside.
Marinate the mutton with curd, salt and ½ tsp of turmeric and keep it aside for 2 hours or refrigerate it.
In a frying pan, add 250 ml of oil and when the oil is hot, add chopped onions and fry till they turn brown and crispy. Keep them aside.
In a saucepan, add washed rice, washed lentils, crushed wheat and 500 ml of water and close the lid. Cook on medium flame for about 5 minutes and then simmer for 20 to 25 minutes till the rice, lentils and wheat get tender. Stir in between. The rice, lentils and wheat should be cooked fully and it should be little mushy.
In a pressure cooker, add oil. Once hot, add all the whole garam masala. Once it starts popping add in chopped onion. When the onions turn brown, add ginger garlic paste. Saute for 1 minute. Now add the chopped tomatoes and fry it nicely.
When tomatoes soften, add turmeric, coriander, cumin powder, salt, red chilli powder, half of garam masala powder and fry it for almost 2-3 minutes or till the nice aroma comes from the masala.
Add the marinated mutton and mix well for about 5-6 minutes or till the oil leaving the mixture. Add chopped coriander, mint leaves, water and close the lid. Pressure cook till 5 to 6 whistles. Now let the meat to cool down.
To the mutton gravy, add cooked and mashed rice, lentils and wheat. Add water, chopped mint leaves, chopped coriander, half of fried onions, salt, black pepper powder, garam masala powder and ghee or clarified butter. Mix thoroughly and close the lid.
Stir frequently to prevent burning. Cook on medium flame for about 5 minutes and simmer for 10 to 15 minutes.
Take out the cooked khichda in a bowl and garnish with ghee, mint leaves, coriander leaves and fried onions along with some chopped green chilly and some lemon wedges beside it.
The other variants of mutton khichda is beef khichda or chicken khichda. Haleem is also a meat dish similar to khichda, which is prepared mainly with broken wheat / dalia and cooked until the meat blends with lentils so it becomes more like a thick soup while khichda is not blended and you are able to see and taste the chunks of meat.
Meat can be replaced with button mushroom (Mushroom Khichda) / soya chunks (Subz Khichda) and rice can be replaced with bajra for vegetarian version.