Cauliflower Preparation:

1. Remove the core of the cauliflower with a sharp knife.

2. Detach the florets by cutting the base of the stems.

3. Rinse thoroughly under cold water to remove impurities.

4. Bring a large saucepan of salted water to a boil.

5. Add cauliflower florets and cook for 8-10 minutes until tender but slightly firm.

6. Drain carefully and set aside.

Preparing the Béchamel:

1. Melt 40 g of butter in a saucepan over medium heat.

2. Add 40 g of flour all at once and whisk vigorously to form a roux.

3. Cook for 2 minutes on low heat, stirring constantly to avoid over-browning.

4. Remove the pan from heat and gradually pour in 450 ml of milk, whisking vigorously to avoid lumps.

5. Return to medium heat, whisking continuously until the sauce thickens.

6. Season with salt, freshly ground black pepper, and a pinch of grated nutmeg.

7. Off the heat, add 115 g of grated cheddar and mix until fully melted.

Assembling the Gratin:

1. Preheat your oven to 240°C (conventional heat).

2. Arrange the cooked cauliflower florets evenly in a gratin dish.

3. Pour the cheddar béchamel sauce over the cauliflower, ensuring full coverage.

4. Sprinkle 1 tablespoon of grated parmesan on top for a golden crust.

5. Bake for 10-15 minutes until the surface is browned and slightly crispy.

6. Serve piping hot on its own or with a green salad for a comforting, balanced meal.