Preheat the oven to 450 degrees F.
Add the broccoli to a large, rimmed sheet tray along with the walnuts, red pepper flakes and garlic, and drizzle with the olive oil. Sprinkle with salt and pepper and toss to coat. Roast until the stems are tender-crisp and lightly golden brown, 15 to 18 minutes.
Recipe courtesy of The Neelys