Preheat the oven to 350°F.
Heat the olive oil in a large skillet over medium heat. Sauté the onion and mushrooms until soft but not browned. Add the green beans and cook just until they begin to soften.
Meanwhile, melt the butter in a medium saucepan over medium-low heat. Add the garlic and cook for 1 minute.
Stir in the cream cheese, heavy cream, chicken broth, Worcestershire, salt and pepper. Simmer, stirring, until smooth and thick enough to coat the back of a spoon.
Pour the sauce over the green beans and stir to coat. Spread in a 9x9 baking dish and sprinkle with the cheddar.
Bake for 30 minutes, adding the fried onions for the last 5 minutes.