Salt the hash brown potatoes, mix with chopped scallions and rosemary (remove the stalk). Grease casserole pots with butter and fill them with ½ of potato mixture.
Chop the mushrooms and place on top of potatoes.
Add stock to both pots.
Shred the mozzarella ball and mix it with hard cheese.
Add ½ of cheese on top of the pots.
Place all the rest of hash brown to the pots and shredded cheese on top.
Put in the oven, covered with the lid or foil. Bake 30 minutes until potatoes are cooked and cheese melted.
Let the casserole cool a little before serving. Serve with chopped parsley on top.
* To make your own hash browns for this casserole recipe, wash and peel 3 small potatoes. Coarsely grate them and leave in a freshly boiled bowl of water for 5 minutes. Drain well. Then follow the instructions. Bake for 8-10 minutes more.** Choose stock to your taste. You can use vegetable or chicken stock.You can use 2 pots for easy servings or double the recipe for one bigger casserole dish.See freezing instructions in the post above the recipe.