Ingredients

• 1 1/2 pounds broccolini (2 large bunches), ends trimmed
• 4 tablespoons olive oil (divided)
• 1 teaspoon kosher salt (divided)
• 1 small sweet onion, finely diced
• 8 ounces cremini or other mushrooms, thinly sliced
• 1/4 cup dry white wine or vermouth
• 1/4 teaspoon freshly ground black pepper
• Grated Parmesan cheese, for serving (optional)

Instructions

1. Preheat the oven to 400°F. Put the broccolini on a baking sheet, drizzle with 2 tablespoons of the oil, sprinkle with 1/2 teaspoon of the salt, and toss to coat evenly, then spread in a single layer. Roast the broccolini, turning once with tongs, for 10 to 15 minutes, until crisp-tender. If the broccolini stems are not uniform in size, remove thinner ones as they are done. Transfer the broccolini to a platter. (The broccolini can be cooked several hours ahead of time and kept at room temperature.)
2. In a large (12 inches or wider), deep frying pan, heat the remaining 2 tablespoons oil over medium heat. Add the onion and cook, stirring occasionally, for about 5 minutes, until starting to soften. Raise the heat to medium-high, add the mushrooms and the remaining 1/2 teaspoon salt, and cook, stirring occasionally, for 7 to 10 minutes, until the mushrooms are golden brown. (The mushrooms will release a lot of liquid before reabsorbing it and browning. Be patient, as the flavor is in the browning.) Add the wine and cook for about 2 minutes more, until the pan is dry. Stir in the pepper.
3. Spoon the mushrooms over the broccolini, then scatter some Parmesan over the top. Serve warm or at room temperature.