Season chicken with salt and pepper. Heat 1 tbs. oil in skillet. Add chicken and cook until most pink has disappeared, stirring a few times. Remove chicken and put in a bowl, set aside. Do not drain.
Add other tbs of oil to pan and onion and 1/2 tsp salt. Stir often until onion is translucent and softened. Stir in garlic oregano and pepper flakes. Cook 30 seconds until fragrant.
Add pasta (I like ziti, penne or rigatoni) and 2 cups of water and the can of broth. Bring to a boil and continue to cook over high heat until liquid becomes thick and syrupy. It will almost be absorbed in 12-15 minutes.
Add broccoli, sundried tomatoes and final 3/4 cup of water. Cover and reduce heat to medium. Cook until broccoli is bright green and almost tender. 3-5 minutes.
Uncover and return to high heat. Stir in cream and 1/2 Asiago cheese and reserved chicken and juices. Simmer uncovered to cook chicken all the way through and thicken sauce. Roughly 2 minutes. Stir in fresh lemon juice and season with salt and pepper to taste.