Corned Beef with Parsley Sauce

Name: Corned Beef with Parsley Sauce
Ingredients: Brine & Rub; 2 quarts water; 3/4 cup kosher salt; 1 tablespoon pink curing salt, such as sel rose or Insta Cure #1; 1/2 cup brown sugar; 3 tablespoons prepared pickling spice; 2 quarts ice water; 5 pounds beef brisket, with the deckle intact; 3 large fresh bay leaves, torn into small pieces; 9 colves garlic, crushed; 3 tablespoons yellow mustard seed; 2 tablespoons coarsely ground black pepper; 1/2 teaspoon ground cinnamon; 1/2 teaspoon ground allspice; 1/4 teaspoon freshly ground nutmeg; 1/4 teaspoon ground cayenne pepper; 1/4 teaspoon coriander; 2 cups warm parsley sauce for serving; Parsley Sauce; 2 tablespoons unsalted butter; 2 1/2 tablespoons all purpose flour; 1 1/2 cups whole milk, warmed; 1/2 teaspoon kosher salt; 1/4 teaspoon freshly ground pepper; Pinch of freshly ground pepper; 1/2 cup chopped parsley