Preheat oven to 350°F. Spray or grease a 3-quart baking dish with coconut oil.
Make cashew cream: put 3/4 cup raw cashews in a 2-cup measuring cup then pour warm or hot water over to make 2 cups. Let side while you cook sausage then blend in a blender on high speed until completely smooth.
Cook sausage in heavy large skillet over medium-high heat until brown, breaking into small pieces with a spoon or spatula, about 5 minutes. Sprinkle arrowroot over sausage, stirring to coat, then add in 1 1/2 cups cashew cream (or 1 1/2 cups coconut cream, whisked). Cook until mixture thickens and comes to boil, stirring occasionally, about 3-5 minutes. Add plenty of fresh black pepper.
In a medium bowl, whisk eggs and add remaining cashew cream (or coconut cream), spices, salt, and 1/3 of the green onions.
In a baking dish, spread hashbrowns evenly, and sprinkle with a pinch of salt. Top with 1/3 of green onions, then sausage mixture, then egg mixture. Bake 45-50 minutes then sprinkle with remaining green onions. A knife inserted in the center won't come out clean because of the creamy sauce, but the surface should be firm. Cut into squares and serve.
You can use one 13.5-ounce can coconut cream instead of cashews, if preferred. Whisk before using; use 1 1/2 cups in the sausage cream sauce and the remainder in the eggs.