Cut the cauliflower into 1 inch thick steaks, line a large baking sheet and add the cauliflower onto the sheet evenly spaced out.
Add the yoghurt, ginger and garlic, coriander, garam masala, chilli powder, turmeric, salt and lemon juice to a bowl and mix well.
Brush the yogurt marinade onto the cauliflower steaks and pieces making sure to get in all the cracks and flipping over to coat both sides.
Pop into the fridge to marinate for your desired amount of time (at least an hour).
Once the marinating time is up put the cauliflower in the oven at 180C for 40 minutes or until the thickest part of the cauliflower is cooked until soft.
Whilst the cauliflower is baking get started on the sauce. Add the olive oil to a pan and fry the diced onion until soft.
Add in one tablespoon of garlic and ginger paste and fry for a minute. Next add in the dry spice powders and sugar. Stir well to make sure the onions are coated.
Now add in the passata or chopped tomatoes and bring to up to heat. Pop the lid on and put on a simmer stirring frequently, make sure to add water as you go if the sauce gets a little too thick. Melt in a knob of butter just before serving.
Once the cauliflower is cooked to perfection grab yourself a serving plate and spread the sauce along the plate and gently place your cauliflower on top.
Top with some more cream and fresh parsley and enjoy!