Step 1: Prepare the Cauliflower

• Preheat your oven to 200°C (180°C fan).
• Bring a large pot of salted water to a boil.
• Add the cauliflower florets and blanch for 4-5 minutes until slightly tender but still firm.
• Drain the cauliflower well and set aside.

Step 2: Make the Cheese Sauce

• In a medium saucepan, melt the butter over medium heat.
• Stir in the flour and cook for 1-2 minutes to form a roux, stirring continuously to avoid burning.
• Gradually whisk in the milk, stirring constantly until the sauce begins to thicken.
• Bring the sauce to a gentle simmer and cook for 3-4 minutes until smooth and creamy.
• Stir in the grated cheddar cheese, Dijon mustard, salt, and pepper, and whisk until the cheese is fully melted and the sauce is velvety smooth. You can add a pinch of nutmeg for extra flavor if desired.

Step 3: Assemble the Dish

• Arrange the blanched cauliflower florets in an even layer in a medium-sized baking dish.
• Pour the cheese sauce over the cauliflower, making sure it’s fully coated.
• Sprinkle the grated Parmesan cheese over the top for a crispy, golden finish.

Step 4: Bake the Cauliflower Cheese

• Place the baking dish in the preheated oven and bake for 20-25 minutes, or until the top is golden and bubbling.
• Remove from the oven and allow it to cool slightly before serving.

Step 5: Serve the Cauliflower Cheese

• Serve hot as a side dish with roast meats or as a comforting vegetarian main course with a green salad or crusty bread.