I think this would be great with a can of Rotel in it to give it a bit of a kick. It does need a bit of something.
First of all, I would saute the chicken first, then remove from the pan. Then add a little more oil and saute the onions and mushrooms. Then stir in a tablespoon of flour to thicken, and mix in throroughly, cooking on medium heat for about 1 minute to get rid of the flour taste. Then slowly whisk in the broth so eliminate any lumps. Then the cream cheese. Then proceed with the rest of the recipe, adding the chicken back into pan; but I would also add about a 1/2 teaspoon of celery seed to the seasonings to give it a little zip.