Rinse spears under cold water and pat thoroughly dry — moisture causes steaming instead of roasting. Trim 1–2 inches from the woody ends, or bend each spear near the base until it snaps at the natural breaking point. Arrange on a rimmed baking sheet, drizzle with olive oil, season with salt and pepper, toss to coat, then spread in a single layer with space between each spear. A crowded pan traps steam and kills browning.

Preheat oven to 218°C and let it fully come to temperature. Place prepared spears on a baking sheet on the center rack. Roast 8–14 minutes: thin spears take about 8 minutes, thick spears 12–14 minutes. No flipping needed, but shake or rotate the pan if you notice uneven browning. Done when tips are golden and slightly crispy and spears show light browning in spots. If still pale and limp, add 2–3 more minutes. Avoid opening the oven door repeatedly.

Asparagus is done when tender to a fork and tips show light browning. They should hold their shape with a slight bite — not limp. Pull the pan immediately and transfer to a plate; leaving spears on the hot sheet overcooks them. Squeeze fresh lemon juice over just before serving. Avoid these mistakes: wet spears before roasting, crowding the pan, and an underpreheated oven — all cause pale, steamed, soft results instead of caramelized ones.