1. In a large pot, bring two quarts water to a boil. Cook pasta according to package directions.
2. Meanwhile, coat a large non-stick skillet with olive oil spray. Heat 1 tablespoon oil in skillet; add carrots and onions. Saute for about five minutes, until vegetables begin to soften. Add pepper and garlic; cook for two minutes. Add spinach, herbs, and salt, cooking for an additional three minutes.
3. Drain pasta, reserving a few tablespoons of cooking water. Immediately toss pasta with vegetable mixture, cooking water, and remaining olive oil. Top with cheese if desired. Serve immediately.