Heat oil in an oven proof pan over high heat.Add mushrooms and onions, season with salt and pepper, and cook 4 min.
Add wine and cook 2 minutes.Stir in garlic and herbs and cook on medium heat for 2 minutes more, then remove pan from heat.
Stir in about half of the grated cheese and half of the cream.
Arrange the potatoes slices over the mushroom mixture.Pour the broth over the potatoes, then top with remaining cream and parmesan cheese.Season with salt and pepper.
Bake uncovered in oven for 40 minutes then turn up heat to 375 F and bake 10 minutes more.Cool 10 minutes before serving.Serve as a side to chicken or beef (or enjoy it as a light lunch with a side salad).