Preheat oven to 375°F.

Trim 2 inches from broccolini stems. If any stalks are thick, slice in half lengthwise.

Spread on a sheet tray, drizzle with olive oil, season with kosher salt, and toss to coat.

Grate parmesan liberally over the broccolini. Roast for 30 minutes, or until crisp at the edges and tender in the center.

While the broccolini roasts, place hazelnuts on a small sheet tray and toast in the oven for 5 minutes, or until golden and fragrant. Let cool, then chop finely.

Heat a small pan over medium heat. Slice lemon in half.

Once the pan is hot, place lemon halves cut side down and sear for 1–2 minutes until well browned. Let cool for 5 minutes, then slice off the charred ends (about ¼ inch thick) for garnish.

Transfer roasted broccolini to a serving plate. Top with chopped hazelnuts and charred lemon slices. Serve warm or at room temperature.