Pre-heat oven to 350 degrees
Heat the first measure of fat in a large skillet over medium heat.
Add the onion and mushroom. Saute for 5 to 6 minutes. Stirring occasionally.
Melt the additional TBSP of fat and stir with the softened veggies.
Sprinkle the cassava flour over and stir until everything is well coated and the flour begins to brown slightly.
Slowly add broth, stirring constantly. Cook an additional 3 to 4 minutes.
Add the onion and garlic granules/powder, coconut aminos, coconut milk, and fish sauce.
Cook an additional minute or two.
Fold in the green beans.
Transfer mixture baking dish.
Bake for 30 minutes.
While it's baking, thinly slice the shallots for the topping and set aside. Melt the palm shortening in a skillet over medium heat.
Add shallots to the oil and fry until golden brown and crispy.
Sprinkle with salt. Place shallots on casserole.