Cook riced cauliflower along with the ghee, salt and pepper and scant 1/3 cup water until the cauliflower is soft.
Pour the cooked cauliflower into a small glass pan and mix in all the other ingredients except 2 tablespoons of grated cheese.
Use this to top off the casserole.
Bake in a 350 oven for 25 mins until the cheese is melted and the sides have browned.
The best way to rice cauliflower is to break it up into florets and put into a blender with plenty of water. Pulse it a few times until the cauliflower is uniformly riced, being careful not to overdo this. The goal isn't to get a cauliflower smoothie here.
Cauliflower and Cheese Casserole https://twosleevers.com/cauliflower-and-cheese-casserole/