Bring a few inches of water to a low boil in a skillet. Add salt and the beans and cook 3-4 minutes to tender-crisp; drain.
Heat the EVOO and butter in a large, deep skillet over medium to medium-high heat. Add the mushrooms and lightly brown them, 7-8 minutes. Add the shallots and garlic and season with salt, pepper and thyme. Stir for 2-3 minutes more; add the flour, stir for a minute, then add the wine. Stir in the stock and thicken. Add the cream and reduce the heat to simmer. Add the cheese, beans and chicken and thicken a bit.
Transfer into a casserole dish and cool. Cover and refrigerate. To cook, bring back to room temperature and bake at 375°F until bubbly, about 50-60 minutes. Top with homemade* or store-bought fried onions.