In a saute pan over medium heat, add broth and pasta. Bring to a boil, cover, and reduce heat to low.
Consult pasta's cooking directions for al dente pasta. Cook pasta until 7 minutes remain, then add vegetables, Italian seasoning, salt, pepper, and red pepper flakes. Stir, cover, and cook for remaining 7 minutes. Pasta and vegetables should be cooked through and most of liquid should be absorbed.(ex: if pasta takes 12 minutes to cook to al dente, cook for 5 minutes, add vegetables, then cook for remaining 7 minutes).
Uncover pan and add heavy cream, lemon juice, and parmesan cheese. Stir and cook for 1 minute, or until cheese has melted.
Remove from heat and allow to set for 5 minutes before serving. Sauce will continue to thicken as it stands.
* To make vegetarian, substitute parmesan cheese with a rennet-free parmesan, vegetarian parmesan, or other Italian hard cheese that is labeled as vegetarian or vegan.