Start by preheating your oven to 400°F (200°C). This high heat is essential for roasting the Brussels sprouts to a crispy, caramelized perfection.
Trim the ends of the Brussels sprouts and remove any yellow or damaged outer leaves. Cut each sprout in half lengthwise to ensure even cooking and more surface area for caramelization.
In a large mixing bowl, combine the Brussels sprouts with the olive oil, maple syrup, salt, and black pepper. Toss until every piece is evenly coated. The maple syrup will add a glossy layer that will turn beautifully sticky and caramelized in the oven.
Spread the Brussels sprouts out in a single layer on the baking sheet, cut side down. This ensures maximum contact with the hot surface, promoting crispiness.
Place the baking sheet in the preheated oven and roast for 20-25 minutes. Halfway through, use a spatula or tongs to flip the Brussels sprouts so they brown evenly. Keep an eye on them during the last few minutes to prevent burning.
About 5 minutes before the end of roasting, sprinkle the chopped walnuts over the Brussels sprouts and return to the oven. This will toast the walnuts lightly and enhance their flavor and crunch.
Once the Brussels sprouts are tender on the inside and caramelized on the outside, remove them from the oven. Serve immediately for the best texture and flavor.
