spaghetti with brocoli sauce

Found this recipe in weight watchers site
2 spray(s) cooking spray
1 Tbsp olive oil
1 medium onion(s), chopped
8 oz uncooked whole-wheat spaghetti
1 cup(s) canned chicken broth
6 cup(s) broccoli, florets, fresh or frozen
1/4 cup(s) low fat cream cheese, softened
1/2 tsp table salt
1/4 tsp crushed red pepper flakes
1/4 cup(s) grated Parmesan cheese, high-quality recommended

Instructions
Coat a large skillet with cooking spray and heat over medium heat; add oil. When oil begins to shimmer, add onions; sauté until onions turn translucent and start to caramelize, about 12 to 15 minutes.

While onions are caramelizing, cook pasta according to package directions. Drain pasta but reserve some cooking liquid. Do not cool pasta with cold water.

Meanwhile, in a large saucepan over high heat, bring broth to a boil. Add broccoli, reduce heat to medium-low and cover tightly; cook for 10 minutes. Remove broccoli from broth with a slotted spoon and add broccoli to sautéed onions; reserve broth.

Add cream cheese to onion-broccoli mixture; stir until cream cheese dissolves. Simmer gently over low heat, about 5 minutes.

Scrape onion mixture into a food processor and add reserved broth, salt and red pepper flakes; puree until smooth.

Place pasta in a serving dish and top with sauce; sprinkle with cheese. Yields about 1 cup per serving.