1/2 cup packed fresh basil leaves, plus a few sprigs, for garnish
1 clove garlic, smashed
1 1/2 cups chopped raw broccoli florets and tender stems (about 4 ounces)
1/4 cup low-sodium vegetable broth
1/4 teaspoon freshly grated nutmeg
1/4 teaspoon red pepper flakes, optional
Juice of 1/2 small lemon (1 tablespoon)
2 tablespoons extra-virgin olive oil
3 tablespoons freshly grated Parmigiano-Reggiano, Romano or grana padano cheese
10 ounces whole wheat or tri-color fusilli
Set the oven to 350 degrees Fahrenheit. On a small baking sheet, spread the nuts out and softly toast them for about 5 minutes. Set apart for cooling.
In a food processor, blend 1/4 cup of the walnuts, the garlic, the red pepper flakes (if using), the nutmeg, the broth, the broccoli, the basil, the 3/4 teaspoon of salt, and the lemon juice until just blended. While the processor is running, add the oil in a slow, steady stream. Puree the mixture until a slightly chunky sauce forms, scraping the sides of the bowl as necessary. When the cheese has been added, add 2 teaspoons and pulse to combine.
In a big pot of salted water, prepare the pasta as directed on the package. Reserve 1/2 cup of the cooking liquid before draining.
In the dry pot or a mixing dish, combine the pasta with the pesto and some of the cooking liquid that has been set aside. If more liquid is required, add it along with extra salt to taste.
Add the remaining 1 tablespoon cheese and divide the pasta among the bowls. Spread the remaining chopped walnuts on top. Serve after adding basil leaves as a garnish.