Preheat the oven to 200°C (180 fan/ Gas 6/ 400°F).
Bring a pan of salted water to a boil and cook the sprouts for 3 minutes. Drain, rinse under cold water to retain colour, and set aside.
600 g Brussels Sprouts
In a large heavy-based saucepan, melt the butter then fry the bacon, thyme leaves, and garlic for 2-3 minutes.
50 g Butter, 200 g Smoked Bacon Lardons, 2 Garlic Cloves, 1 teaspoon Thyme Leaves
Stir in the flour and cook for 2 minutes.
50 g Plain Flour
Turn the heat up, whisk in the milk and continue to stir until the sauce thickens. It should coat the back of a wooden spoon.
700 ml Milk
Take the sauce off the heat and stir in the grated cheese, dijon mustard, grated nutmeg, and salt & pepper.
2 teaspoon Dijon Mustard, ¼ teaspoon Grated Nutmeg, 200 g Cheddar, ½ teaspoon Salt, ¼ teaspoon Black Pepper
Mix in the cooked sprouts then pour the cheesy sprouts into a baking dish.
Mix together the breadcrumbs, grated Parmesan and thyme leaves and scatter over the top of the gratin. Bake in the oven for 20-25 minutes until the top is golden brown and the cheese sauce is bubbling.
50 g Dried Breadcrumbs, 3 tablespoon Grated Parmesan, 1 teaspoon Thyme Leaves