Heat your oven up to 200°C.
Cut the cauliflower florets from the stem and boil in salted water for 2-3 minutes. Drain and set aside.
Melt the butter in a pan over a medium heat. Lightly crush the cumin seeds and add them to the butter to infuse as it melts.
Add in the flour and mix well to combine into a paste, called a roux. Cook this off for 1-2 minutes.
Add the milk in gradually, pouring in a little bit at a time and mixing in with the roux to combine. Add as much milk as you need to get a silky sauce that coats the back of a spoon.
Add in the nutmeg, smoked paprika and English mustard alongside some salt and pepper. Mix well.
Add in all of the grated cheddar and 30g of the grated parmesan. Mix consistently to let the cheese melt into the sauce. Add more milk if needed to loosen the sauce until it runs smoothly again.
Add the cauliflower to the cheese sauce and mix well. Transfer it to a roasting dish.
Mix the breadcrumbs, garlic granules, dried thyme and remaining parmesan together. Season with salt and pepper and scatter over the top.
Place the dish into the oven and leave for 20-25 minutes. It is done when the sauce is bubbling and the crumb on top has crisped up!