Creating Garlic Parmesan Roasted Brussel Sprouts is straightforward if you follow these simple steps:

1. Preheat Your Oven: Set your oven to 400°F (200°C) to get it ready for roasting.
2. Prepare Brussels Sprouts: Trim the ends of the Brussels sprouts and slice them in half.
3. Mix Ingredients: In a large bowl, combine the halved Brussels sprouts with olive oil, minced garlic, salt, black pepper, and red pepper flakes if using. Toss until evenly coated.
4. Prepare Baking Sheet: Spread the Brussels sprouts in a single layer on a baking sheet lined with parchment paper. This helps the sprouts roast evenly.
5. Roast in the Oven: Place the baking sheet in the oven and roast the sprouts for about 25-30 minutes or until they are crispy on the outside and tender on the inside. Stir them halfway through the cooking time to ensure even roasting.
6. Add Parmesan: In the last 5 minutes of roasting, sprinkle the grated Parmesan cheese over the sprouts and return them to the oven. Continue roasting until the cheese is melted and slightly golden.
7. Serve and Enjoy: Once done, remove the baking sheet from the oven. Allow to cool for a couple of minutes before serving.

These steps will guide you in creating this amazing garlic-infused side dish effortlessly.