• Prepare the cauliflower: Bring a large pot of water to a boil, then add the salt. While waiting, cut the cauliflower into florets and the stem into small cubes. Add the stem pieces to the boiling water and cook for 2 minutes. Then, add the florets, bring the water back to a boil, and cook for 5 minutes. Once done, drain the cauliflower very well.

  2 lbs cauliflower / 1 kg + ½ tablespoon fine sea salt
• Meanwhile, preheat the oven to 350°F/180°C and prepare the white sauce.

White sauce:

• Heat the milk in the microwave or in a small pot on the stovetop.

  2 cups whole milk / 500 ml
• Make white sauce: Melt the butter in a small saucepan. Sprinkle the flour over the butter and stir for 1 minute until it turns slightly golden. Slowly pour in the hot milk, stirring constantly to avoid lumps.

  2 tablespoons butter / 30 g + 2 ½ tablespoons all-purpose flour/ 20 g + milk
• Simmer the sauce for about 10 minutes, stirring occasionally, until it thickens slightly.
• Add the grated cheese and mustard and stir until melted. Season with nutmeg, salt (generously, taste), and pepper, then mix in the chopped parsley.

  1 ½ cups cheese / 150 g + 1 tablespoon Dijon mustard + a few gratings of nutmeg + fine sea salt and ground black pepper + 2 tablespoons parsley

Cauliflower gratin:

• Combine ingredients: Lightly grease the baking dish with butter. Place the cauliflower into the dish and pour the white sauce over it. Gently stir to combine.
• Add topping: In a small bowl, mix the Parmesan cheese and breadcrumbs, then sprinkle the mixture evenly over the cauliflower. Dot the top with small pieces of butter.

  3 tablespoons Parmesan + 2 tablespoons dried breadcrumbs + 1 tablespoon butter
• Bake for 25 minutes or until the top is golden. If it's not golden enough, increase the oven temperature to 400°F (200°C) and bake for an additional 5 minutes or until the crust turns golden.
• Rest: Let the cauliflower in white sauce sit for 5 minutes before serving.