Wash Brussel sprouts. Peel off any yellow leaves. Trim off the stem.
Cut Brussel sprout in half. Look at the halves, and discard any undesirable ones.
Dice the onion, you can add more if desired.
Place cut Brussel sprouts and onions in a bowl and drizzle olive oil on them, and give them a stir. Season them with salt and pepper. Lay the Brussel sprouts on the baking sheet, make sure they are in one layer.
Roast for approximately 25 minutes.
Want to change up the recipe, here are some suggstions.
Change up the seasonings, a touch of lemon zest after cooking will brighten up the flavors.
Add a healthy dose of freshly ground black pepper.
Add a sprinkle of Pecorino Romano cheese after removing from the oven.