Steam the cauliflower for 10 minutes. Remove from the heat and set aside to cool. Can be pre-cooked and kept cold in the fridge, if you wish.
Heat 2 tbsp of the oil in a skillet over medium heat. Sauté the leek for 2 minutes, add the speck and continue cooking for 5 minutes, stirring frequently. Set aside to cool.
Preheat oven to 190°C. Grease and line 2 loaf pans, a large baking dish or simply use large muffin cups.
Combine the polenta, flour, baking powder, bicarb, salt, cheeses, chives, cauliflower and cooled leek & speck in a large mixing bowl. Toss gently to mix well.
In another bowl whisk together the yoghurt, cream, eggs and remaining 2 tbsp oil. Pour this over the dry ingredients and mix well to combine. Spoon mixture into the prepared baking dishes and bake for 30-40 minutes, or until golden and cooked all the way through.
Remove from baking dish when cool enough to handle. Can be eaten at room temperature, but is best when warm.