Preheat your oven to 180°C.
Cut the cauliflower into florets and pop into a baking dish, then set aside. Make sure the baking dish has high edges and its filled well with the cauliflower pieces.
Melt the butter in a small saucepan over a medium heat and add the brown rice flour. Stir constantly and allow it to cook for 30 seconds, it will form into a sandy paste. Add half of the almond milk and whisk until you have a thick paste and no lumps. Add the remaining almond milk along with the stock and whisk until combined, make sure there are no lumps. Add the wholegrain mustard and garlic and continue whisking until you have a lovely thick sauce, this will take 10-15 minutes. Remove from the heat and add 100g of grated cheese, sea salt and turmeric powder. Stir until the cheese has melted and it’s well combined.
Pour the sauce over the cauliflower, top with the leftover cheese and bake in the oven for 40 minutes, until golden brown on top.