Preheat the oven to 325 degrees F.

Place the butter in a large cast iron skillet and heat butter while whisking until small pieces of brown flecks appear, this is brown butter. Remove 1/4 cup from the skillet for drizzling over the top before serving.

Sauté the celery, onion and mushrooms in butter and spices until tender and translucent.

Add the ground pork and saute while breaking up pieces until pork is cooked through and no longer pink, about 4 minutes. Cut up the keto bread into small 1 centimeter cubes.

Place the keto bread cubes in the pan with the sausage mixture. Add the broth and mix well (you can add more if desired). Season to taste with salt and pepper. Stir in the egg.

Bake, covered, in a greased 1 1/2 to 2 quart casserole for 35-40 minutes.

Uncover and bake for 5-10 more minutes until golden brown on the top.

Drizzle another 1/4 cup brown butter sauce over the top if desired.