Preheat oven to 425°F (220°C)
Trim ends of Brussels sprouts and remove any yellow outer leaves
Cut sprouts in half (or keep small ones whole)
Pat sprouts dry
Toss with olive oil, salt, and black pepper
Optional: add garlic powder and/or red pepper flakes
Spread cut-side down on a baking sheet lined with parchment (single layer)
Roast 20–30 minutes, until browned and tender
Flip halfway through for more even browning
Optional: add balsamic vinegar or lemon juice for the last 2–3 minutes
Optional: toss with grated Parmesan immediately after roasting
Serve hot