Preheat the oven to 180ºC

Place the cauliflower florets in a saucepan and add 1 tsp salt. Cover with water and simmer for 15 minutes, until the florets are soft. They should be easily pierced. Drain and set aside in a colander to dry.

Cut several round slices, each 1/4 inch, off one end of the onion and set aside.

Coarsely chop the rest of the onion and place in a small pan with the oil and rosemary and chilli flakes (if using).

Cook for 10 minutes over medium heat, stirring from time to time, until soft. Remove from the heat and set aside to cool.

Transfer the onion to a large bowl, add the eggs and basil, whisk well, and then add the flour, baking powder, turmeric, parmesan, 1/2 tsp salt and plenty of pepper.

Whisk until smooth before adding the cauliflower and stirring gently, trying not to break up the florets.

Line the base of a 24 cm springform cake pan with parchment paper.

Place in the center of the oven and bake for 45 minutes until golden brown and set; a knife inserted into the center of the cake should come out clean

It needs to be served just warm, rather that hot or room temperature. Enjoy.