Saute the onions and garlic in the butter until the onions are translucent.
Add the remaining soup ingredients. Stir to incorporate.
Add the steamed green beans to the pot with the soup and cook for 10-15 minutes. The soup will thicken and the green beans will be flavorful and tender.
For the Keto Crunchy Topping
Add all of the ingredients to a food processor or blender.
Pulse 2-3 times to blend the topping ingredients and create some crunchy bits.
Assemble the Casserole
Add the green bean and mushroom soup to a baking dish
Top with the mozzerella cheese and then the keto crunchy topping
Bake uncovered for 10-15 minutes or until the cheese is melted, bubbly, and browned.