Mushroom-Stuffed Potato Patties

Potato Dough

• 20 oz water
• 28 oz russet potatoes peeled, cut into pieces (1 in.)
• 2 oz Parmesan cheese, cut into pieces
• 1 large egg
• 2 oz bread crumbs
  or 2 oz panko bread crumbs
• 2 sprigs fresh parsley, leaves only (optional)
• 2 tsp Dijon mustard
• 1 tsp salt
• ¼ tsp ground black pepper

Mushroom Filling

• 2 oz yellow onions, cut into pieces
• 2 garlic cloves
• ½ oz olive oil
• 5 oz fresh mushrooms (e.g. chanterelles, boletes, oyster mushrooms), sliced
  or 5 oz fresh button mushrooms, sliced
• 4 sprigs fresh parsley, leaves only, chopped
  or 4 sprigs fresh dill, leaves only
• 2 oz grated cheese (Monterey Jack, Cheddar, etc.)
• 2 oz bread crumbs
• vegetable oil, to fry
• sour cream, to serve