Trim and cut green beans. Then, add to a pot of boiling water and cook for five minutes. Drain and pour in ice water to stop the cooking process.
1
Melt butter and add the mushrooms, stir to coat and cook until reduced and browned, about 10 minutes. Stir occasionally. Remove from skillet and set aside.
2
Melt more butter and whisk in flour and garlic. Then, pour in the cream, chicken stock, seasonings and mushrooms. Cook until thickened and stir in Parmesan.
3
Mix in the green beans, water chestnuts and fried onion with the cream. Pour into a baking dish and top with more fried onions. Bake until hot and bubbly.
4