Wash and dry zucchini thoroughly — surface moisture causes steaming, not roasting. Slice into rounds or half-moons about ½ inch thick; thinner slices go floppy, thicker ones hold shape and caramelize better. Toss in a bowl with olive oil to coat evenly. Season with salt and pepper just before spreading on the pan — salting early draws out moisture and makes zucchini soggy. Add dried Italian seasoning or garlic if desired.

Preheat oven to 218°C with the rack in the upper third. Line a rimmed baking sheet with parchment. Spread seasoned zucchini in a single layer — no crowding. Use two pans for a large batch. Roast 12–18 minutes. Check at 12 minutes. Flip once at the halfway point if you want browning on both sides; pieces are ready to flip when they release cleanly from the parchment. Thinner slices finish near 12 minutes; ½-inch cuts may need the full 18. Watch edges and undersides, not just the clock.

Done when edges are golden brown and centers are fork-tender. Pieces should look slightly shrunken and caramelized — not pale or wet. If soft but not browned, give it 2–3 more minutes; browning is the flavor cue. Serve immediately — zucchini releases moisture fast and softens as it sits. Finish with a squeeze of lemon, Parmesan, or fresh herbs. Key mistake to avoid: a crowded pan causes steaming, not browning. Pieces must not touch.