1. Put a large pot of salted water to boil.
2. Wash and cut cauliflower into about an inch and a half big florets making sure all florets are of the same size for even cooking.
3. Add the cauliflower florets to boiling water. Keep heat high and wait till the water starts to boil again. Keep boiling on high for another minute at this point. Cauliflower floret should be tender crisp and not too soft as they will cook again later.
4. Drain well and keep aside to let it cool.
5. Meanwhile coarsely dry grind sesame seeds. Slit green chillies into half lengthwise and cut ginger into long thin strips.
6. When cauliflower cools a bit, sprinkle salt, turmeric powder, amchoor powder and ground sesame seeds over it and using a spatula mix it thoroughly to work them in.
7. In a large pan or wok heat the olive oil and add the ginger and green chillies. Saute for about 30 seconds.
8. Now add the cauliflower and fry on high for 2-3 minutes mixing oil and ginger well into it.
9. Reduce the heat to medium and continue frying and mixing for another 3 minutes till all the flavors blend into the florets.
10. Remove from heat and let stand for at least and hour before serving. Garnish with fresh coriander. Serve hot or warm with roti or naan.