01 - Set the oven to 425°F and line a baking sheet with parchment paper.
02 - Combine halved Brussels sprouts with olive oil, sea salt, black pepper, and optional seasonings in a large bowl; toss to coat thoroughly.
03 - Place sprouts cut-side down on the prepared baking sheet in a single layer.
04 - Cook for 20 to 25 minutes, turning once halfway through, until edges are browned and crispy.
05 - Remove from oven and immediately sprinkle with Parmesan, parsley, and lemon zest if desired; serve while warm.