- 12 ounces (4 to 5 cups) rigatoni
- 2 medium red onions, sliced into 1/2-inch-thick rings
- 2 large red bell peppers, cut into quarters
- 1 tablespoon olive oil
- kosher salt and pepper
- 1 bunch spinach, stems trimmed, or one 5-ounce package
- 1 cup (about 3 1/2 ounces) grated Parmesan
- 3/4 cup basil leaves, thinly sliced
- Cook the pasta according to the package directions. Reserve 1 cup of the cooking water; drain the pasta and return it to the pot.
- Meanwhile, heat grill or grill pan to medium-high. In a large bowl, toss the onions, bell peppers, oil, and ½ teaspoon each salt and pepper.
- Grill the vegetables, turning occasionally, until tender, 8 to 10 minutes. Transfer to a cutting board and cut into bite-size pieces.
- Add the grilled vegetables, spinach, reserved pasta water, and ¾ cup of the Parmesan to the pasta and toss to combine.
- Top with the basil and the remaining ¼ cup Parmesan before serving.