Rigatoni with Grilled Peppers and Onions

(yes, this is a pic from the magazine)

I'm always looking for a recipe without meat, and this looks delicious! I haven't made it yet, but I'll be getting the ingredients next time I'm at the store.

2 medium red onions, sliced into 1/2inch-thick rings
2 large red bell peppers, cut into quarters
1 tbls olive oil
Kosher salt and pepper
12 ounces (4 to 5 cups) rigatoni
1 bunch spinach, stems trimmed or one 5-ounce package
1 cup (about 31/2 ounces) grated cheese
3/4 cup basil leaves, thinly sliced

1. Bring a large pot of water to a boil. Heat a grill or girill pan to medium-high
2. In a large bowl, toss the onons, bell peppers, oil, 1/2 tsp salt, and 1/2 tsp pepper. Grill, turning occasionally, until tender 8-10 mins. Transfer to cutting board and cut into bite size pieces
3. Cook the pasta according to the package directions. Reserve 1 cup of the cooking water, drain the pasta, and return the pasta to the pot.
4. Add the grilled vegetables, spinach, the reserved pasta water, and 3/4 cup Parmesan to the pasta and toss to combine. Top with basil and the remaining Parmesan before serving.

hands on time:25 mins, serves 4 (according to the magazine!) p.s. I hate spinach, so I'll be leaving that out!