Preheat the oven to 400°F (200°C). Optionally line a large rimmed baking sheet with parchment paper for easy clean up. (If using an air fryer preheat to 375°F (190°C).)

Wash the broccoli and dry it thoroughly. Cut the head into medium-sized florets, roughly 1.5 to 2 inches across. Peel and slice the stems if using.

Add the florets to the sheet pan. Drizzle with olive oil and sprinkle with salt and pepper. Toss with your hands until every piece is lightly coated. Spread the broccoli in a single layer with space between the pieces. Do not overcrowd the pan.

Roast for 20 to 25 minutes, until the edges are golden brown with some charring on the tips and the stems are tender when pierced with a fork.

Remove from the oven. Squeeze fresh lemon juice over the top if desired and sprinkle with parmesan if using. Taste and add more salt if needed. Serve immediately.