Orecchiette with Roasted Broccoli and Walnuts

I tried this recipe last night from last month's Real Simple magazine. I really liked it, it had great flavor, and is vegetarian! I whipped it up with a simple fruit salad for a healthy dinner.

12 ounces orecchiette or some other short pasta (3 cups)
1 bunch broccoli (1 1/2 pounds) cut into small florets
1/2 cup walnuts, roughly chopped
1/4 cup olive oil
2 garlic cloves, chopped
Kosher salt and black pepper
2 Tbsp. unsalted butter
1/4 cup grated Parmesan (1 ounce)
1. Heat oven to 400 F. Cook the pasta according to the package directions. Reserve 3/4 cup of the cooking water, drain the pasta, then return it to the pot.
2. Meanwhile, on a rimmed baking sheet, toss the broccoli, walnuts, oil, garlic, 1/2 tsp salt and 1/4 tsp pepper. Roast, turning once, until the broccoli is tender, about 18 to 20 minutes.
3. Toss the pasta with the broccoli mixture, butter, and 1/2 cup of the reserved pasta water. (Add more water if the pasta seems dry.) Sprinkle with the Parmesan before serving.