Preheat and prep: Heat the oven to 425°F (220°C). Line a large baking sheet with parchment or foil and lightly oil it. A hot pan helps the florets crisp up.

Cut uniform florets: Trim the cauliflower into bite-size pieces, about 1.5 inches. Even sizes mean even roasting, so they finish at the same time.

Dry the cauliflower: Pat the florets very dry with paper towels. Moisture is the enemy of crispiness.

Mix the coating: In a large bowl, combine olive oil, minced garlic, salt, pepper, smoked paprika, and red pepper flakes. Stir in cornstarch until no dry spots remain.

Toss to coat: Add the florets and toss thoroughly so every piece is lightly coated. Sprinkle in the parmesan and toss again to distribute.

Spread on the pan: Arrange florets in a single layer with space between them. Overcrowding leads to steaming instead of roasting.

Roast, then flip: Bake for 15 minutes. Flip each piece with tongs or a spatula, then roast another 10–12 minutes, until deeply golden and crisp on the edges.

Finish with freshness: Right out of the oven, sprinkle with lemon zest, a squeeze of lemon juice, and extra parmesan. Toss gently on the pan.

Garnish and serve: Shower with chopped parsley and taste for salt. Serve hot with your favorite dip, or alongside roasted chicken or fish.