Preheat oven to 350 degrees. Grease a casserole dish and set aside for now.

Place green beans in a microwave-safe dish with a little water. Steam in the microwave for around 4 minutes. You want them to still be crisp and tender.

Meanwhile, heat butter in a large skillet over medium heat. Add onion and mushrooms. Cook for 5-7 minutes, until both are tender.

Add the garlic, white wine, and Dijon mustard. Cook for a minute.

Stir in cream cheese, chicken stock, and cheddar. Continue cooking over medium heat for another few minutes, stirring frequently, until everything is well combined.

Mix with green beans and then pour everything into the casserole dish. Bake at 350 degrees for 20-30 minutes, until everything is hot and bubbly. If desired, add an optional topping once you remove it from the oven. Enjoy!