Spaghetti & Spinach with Sun-Dried Tomato Cream Sauce

5 ounces baby spinach, coarsely chopped
8 ounces whole-wheat spaghetti
½ cup slivered oil-packed sun-dried tomatoes, plus 1 tablespoon oil from the jar
½ cup halved and thinly sliced onion
3 cloves garlic, minced
¼ teaspoon crushed red pepper
¼ teaspoon salt
¼ teaspoon ground pepper
1 cup low-sodium vegetable or chicken broth
½ cup sour cream
¼ cup grated Parmesan cheese
1 tablespoon unsalted butter

Step 1: Place spinach in a large colander in the sink. Bring a large saucepan of water to a boil over high heat. Add spaghetti and cook according to package directions. Drain the pasta over the spinach; toss to wilt the spinach.
Step 2: Meanwhile, heat oil in a large skillet over medium heat. Add onion and tomatoes; cook, stirring, until softened, about 3 minutes. Add garlic, crushed red pepper, salt and pepper; cook, stirring, for 1 minute. Increase heat to medium-high and add broth; cook, stirring, until reduced by about half, about 2 minutes. Stir in sour cream, Parmesan and butter. Add the spaghetti and spinach; toss to coat well.