Brussels Sprouts Gratin With Walnut Crumble Recipe

Topped with a crunchy walnut crumble, this Brussels sprouts gratin is cooked in a creamy and cheesy bechamel sauce. Recipe developer Annabelle Randles likes to infuse an extra boost of flavor to this dish by adding some wholegrain mustard in the sauce, which adds a tangy depth without being overbearing. This dish makes a warming and delicious side dish for winter Sunday lunch, Thanksgiving, Christmas, or any special occasion.

It is fair to say that aside from the holiday season, Brussels sprouts are often met with little enthusiasm around the dinner table. You either love them or hate them. They are one of Randles' favorite winter vegetables because they are so versatile. To harness their full flavor, forget eating them blanched and try roasting, sauteing, grilling, or even air-frying them instead. They can even be eaten raw, finely shredded in salads and slaws. Low in calories, Brussels sprouts are rich in vitamins, minerals, fiber, and antioxidants, making them a valuable addition to a balanced and nutritious diet. 

Brussels sprouts are at their peak during the fall and winter. For the best flavor, Randles recommends shopping for sprouts while they are in season, and selecting firm and compact sprouts with vibrant green color while avoiding sprouts that are yellowing.

Besides Brussels sprouts, you will need a few more ingredients to round out the recipe. The Brussels sprouts are cooked in a rich and creamy béchamel sauce made with butter, all-purpose flour, milk, nutmeg, garlic, wholegrain mustard and cheddar cheese. For the crumble topping you will need panko breadcrumbs, Parmesan, walnuts, and dried thyme.

To create a light and crunchy texture, Randles prefers using panko breadcrumbs for the crumble topping. You can substitute them with regular breadcrumbs. The crumble will not be as crispy but still very enjoyable. 

Bring a pan of water to a boil.

Once boiling, add ½ teaspoon of salt and cook the Brussels sprouts for 5-8 minutes. They should be soft but still firm.

Drain the sprouts well and set aside.

In the meantime, make the bechamel. Melt the butter in a small saucepan over medium heat.

Whisking continuously, stir in the flour. Cook until the flour turns golden, about 2 minutes.

Whisk in the milk, nutmeg, and garlic. Reduce the heat to medium-low and whisk until the sauce thickens, about 5-10 minutes.

Remove the pan from the heat. Stir in the mustard and grated cheddar cheese. Once the cheese has melted, season with salt and pepper. Set aside.

Preheat the oven to 400 F.

Prepare the walnut crumble: In a mixing bowl, combine the breadcrumbs, Parmesan, walnuts, and thyme. Set aside.

Add the Brussels sprouts to an oven-proof 9x9-inch baking dish.

Cover the sprouts evenly with the bechamel sauce.

Scatter the walnut crumble on top.

Bake the gratin until golden, about 20-25 minutes.

Leave to rest outside the oven for 5 minutes before serving.

This Brussels sprouts gratin with walnut crumble makes a great side dish for roasted chicken, turkey, pork, salmon, or even as part of a vegetarian feast. At its simplest, Randles likes to serve it with a side of whole grains such as brown rice, quinoa, barley, farro, or freekeh as well as a slice of crunchy bread to soak up the creamy bechamel sauce. This dish pairs well with a crisp white wine (such as chardonnay or sauvignon blanc) as well as a light fruity red wine such as a merlot. 

Though this dish does feature a green vegetable at its core, it is ultimately a very rich, creamy, and decadent dish, so it's a good idea to pair it vegetable side to help cut some of that richness. Randles recommends a simple green salad with bright cherry tomatoes to help liven up your plate and bring some freshness.

You can definitely make a vegan version of this Brussels sprouts gratin with walnut crumble by swapping the butter, milk, and cheese for dairy-free alternatives. A neutral-tasting plant-based milk such as plain soya or oat milk will work best. Randles also recommends adding nutritional yeast to the bechamel and crumble topping to enhance the overall flavor of this gratin. 

Nutritional yeast is a deactivated yeast that is often used as a seasoning or flavor enhancer, especially in vegan and vegetarian cooking. It is known to be filled with umami and is ideal for adding a cheesy and savory depth to plant-based dishes. Very often, nutritional yeast is fortified with B-vitamins, including vitamin B12, making it an essential addition to any pantry. Nutritional yeast is widely available and can be purchased from grocery stores (especially those with a focus on natural and organic products), health food stores, and online retailers.