Preheat oven to 425F (220C).

Trim ends of brussels sprouts (just cut off any browning) and remove any dirty outer leaves. Cut brussels sprouts in half lengthwise and place in a large bowl.

Drizzle brussels sprouts with olive oil and sprinkle with salt and pepper. Toss until sprouts are all coated with oil.

Scatter brussels sprouts evenly over a baking sheet.

Transfer baking sheet to center rack of oven and bake for 15 minutes. Use a spatula to turn brussels sprouts then return to oven and bake another 10-15 minutes, until sprouts are deep brown in spots and are tender when pierced with a fork.

Add additional salt and pepper to taste, as needed.