Preheat the oven on medium broil and line a large baking tray with parchment paper. Grease a 9?13-inch or other 3-quart baking dish with some oil and set aside.

Thoroughly wash the cauliflowers and pat the excess moisture with a paper towel. Trim the stem off the cauliflower and cut into florets.

Arrange the cauliflower florets in the prepared baking tray, spray with Cooking Oil Spray, and season with the Kosher Salt and ? teaspoon black pepper; toss to coat well.

Broil for 12-15 minutes, or until charred and tender-crisp.

While the cauliflower is baking, in a heavy skillet, heat the Olive Oil on medium heat. Add the minced garlic and cook for 1 minute, until fragrant.

Add the Gluten-Free Flour and whisk quickly until a white froth begins to appear on the top.

Carefully and slowly pour in the Milk; continue whisking until the mixture starts to bubble. Reduce the heat to low and let it simmer until the sauce thickens.

Once the sauce is thick and creamy, remove from the heat, stir in the Grated White Cheddar, Freshly Grated Nutmeg, and mix thoroughly until the cheese is completely melted.

Adjust the seasoning to taste.

Remove the cauliflower from the oven and carefully transfer it into the prepared baking dish.

Pour the hot bubbling sauce on top; mix until well combined. Top with Grated Parmesan Cheese.

Change the oven settings to 375?F fan-assisted. Bake for 15-20 minutes until hot and bubbly.

Remove from the oven and let cool at room temperature for about 5 minutes. Garnish with Freshly Chopped Parsley and Chili Flakes if desired. Serve hot.