Ingredients

• 1 large onion, thinly sliced (2 1/4 cups)
• 1/2 pound fresh poblano chiles, stemmed, seeded, and thinly sliced lengthwise
• 2 tablespoons olive oil
• 1 cup chopped bottled roasted red peppers
• 1 pound ziti or penne
• 1 tablespoon chopped canned chipotles in adobo
• 1 1/2 cups sour cream
• 1 cup chopped scallions (about 1 bunch)
• 1/4 cup chopped cilantro
• raw green (hulled) pumpkin seeds (pepitas), toasted

Instructions

1. Cook onion, poblanos, and 1/2 teaspoon salt in oil in a heavy medium pot over medium heat, covered, stirring occasionally, until onion is golden, 8 to 10 minutes. Add red peppers and cook, stirring occasionally, until onion is tender, 2 to 3 minutes.
2. Meanwhile, cook ziti in a pasta pot of boiling salted water (2 tablespoons salt for 6 quarts water) until al dente. Reserve 1 cup cooking water, then drain ziti.
3. While ziti cooks, purée chipotles with sour cream in a blender.
4. Add purée to onion mixture with scallions, cilantro, 1/4 cup cooking water, and 1/2 teaspoon salt and bring to a simmer, stirring. Add ziti and toss, moistening with additional cooking water if desired. Season with salt.