Trim off the very end of the sprouts and pull off any outer leaves that have yellowed. Cut in half (or quarters if sprouts are larger than ping-pong ball size).
Toss in a large bowl with olive oil, salt, and pepper. Shake sprouts in a single layer onto a large baking sheet lined with parchment paper. Roast for 30-40 minutes or until tender and dark brown on edges, tossing halfway through. Sprinkle with grated parmesan (if using) and serve.
Recipe by Baked In at https://www.baked-in.com/2011/12/16/roasted-brussels-sprouts/