Preheat the oven to 350 degrees F and grease a 9x13" baking dish *see note below. In a large skillet, cook and crumble the breakfast sausage. Then, drain the grease and set the sausage aside in a separate dish.
Return the skillet to the stove over medium high heat. Add the butter. Once the butter has melted add the chopped mushrooms, water chestnuts, hemp hearts, and cauliflower rice.
Cook, stirring occasionally until the mushrooms are softened and the cauliflower rice is heated through.
Reduce the heat to low and stir in all of the spices and chicken broth concentrate.
Return the cooked and crumbled sausage to the pan, then stir in the sour cream.
Remove from the heat and adjust seasoning to taste.
Transfer to the baking dish and cook uncovered in the preheated oven for 15-20 minutes until the top is slightly browned and crisp.
Baking is not required but with the toast the top of the casserole and gives the casserole a great flavor. The casserole can also be assembled ahead of time and then baked to heat through to make a quick weeknight supper. (if you are baking from cold or frozen, be sure to add additional baking time)