- Half and slice the eggplant, halve mushrooms, grate large onions, crush garlic, slice medium onions then keep aside.
- Cook carrots, potato, and okra in a pan of boiling, salted water for about 8 minutes. Drain and place in a large bowl.
- Then mix with mushrooms, celery and eggplant.
- Mix yogurt with grated onions, turmeric, ginger, garlic and curry powder then put over the vegetables. Leave for 2 hours to marinate in a cool place.
- Take a heavy-based frying pan, heat butter in it then put sliced onions and cook at a low heat for 6 minutes or until golden brown. Reserve few onions from the pan for garnish.
- Take a large pan of boiling water, cook rice in it for about 7 minutes, drain and set them aside.
- Then put marinated vegetables to the onions and cook for 10 minutes.
- Place half of the rice in a 2 litre casserole dish. Put the vegetables on top and cover with remaining rice.
- Cover the lid and cook in a preheated oven for 25 minutes at a temperature of 375?F, or until the rice is tender.
- Dish out the biryani in a serving platter. Garnish with reserved onions and coriander then serve.