Using a medium stock pot, heat the avocado oil on medium heat. Saute the mushroom and garlic for 4-5 minutes or until tender. Add the arrowroot starch and stir to coat the mushrooms.

Pour in the remainder of the ingredients, mix well to combine and bring to a simmer for about 10 minutes or until the soup thickens.

Remove from heat and allow to cool before using an immersion blender or high-speed blender to fully blend the soup. Set aside.

Fill a large stock pot about two-thirds of the way full and bring to a boil. Add the green beans and cook for 10 minutes or until fork tender. Strain and set aside.

Preheat the oven to 375 F and lightly grease an 8x8" casserole dish. Add the green beans to the casserole and pour the mushroom soup over top. Toss to coat.

Bake the casserole in the preheated oven for 15-20 minutes, while simultaneously cooking the fried onions (see below). Once the casserole is fully cooked, top it with the fried onions and serve.

Form the coating by combining two flours, salt, and pepper in a bowl and set aside. Set up a station with the coating and another bowl with the coconut milk.

Using a large deep skillet, heat a generous amount of avocado oil over medium-high heat.

Begin coating the onions by dipping them in the coconut milk, and then the flour mixture. Carefully drop in the onions and cook for about 2 minutes of each side before setting aside. You'll fry all of the onions in about 3-4 small batches.

Set the fried onions on a paper towel before adding them to the top of the green bean casserole.