In a bowl add 4 cups water with 2 teaspoons salt. Immerse cauliflower for about ½ hour and drain.
Grand together poppy seeds and cashew nuts into a paste, adding a little water (3 teaspoons) from time to time.
Separately grind together ginger, garlic and chillies into a paste.
Heat oil in cooker for about 2 minutes. Add onions any fry till golden brown.
Add ginger-garlic paste, tomatoes, turmeric coriander, cumin and chilli powders, ¼ cup water and remaining salt(2 ½ teaspoons). Cook till tomatoes are pulpy, stirring occasionally.
Add 1 teaspoons curd. Stir and fry until curd is well blended (approximately ½ minute). Add remaining curd in the same way, a tablespoon at a time till all curd is used. Fry till oil shows separately (approximately 3 minute).
Add cauliflower. Stir and fry for about 5 minutes, ending with cauliflower stump down. Away from heat, stir in cashew nut paste and remaining water (1/2 cup) all round cauliflower.
Closed cooker . Bring to full pressure on high heat. Reduce heat and cook for 2 minutes.
Remove cooker from heat. Release pressure with slight lifting of vent weight.
Open cooker. Transfer cauliflower onto a serving dish. Pour masala evenly over cauliflower. Serve hot, garnished with coriander leaves.