Zingerman's Reuben Sandwich

INGREDIENTS

• 1 tablespoon plus 1 teaspoon minced Spanish onion
• 1/4 teaspoon Worcestershire sauce
• 2 teaspoons chopped curly parsley leaves
• 4 tablespoons butter, melted
• 12 ounces Russian dressing, recipe follows
• 12 ounces sauerkraut
• 2 tablespoons sour cream
• 1/2 teaspoon fresh lemon juice
• 1 loaf unseeded and unsliced Jewish Rye bread
• 2 pounds corned beef, sliced (see Cook's Note)
• 3/4 cups mayonnaise
• 1 tablespoon plus 1 teaspoon minced dill pickle
• 12 slices Swiss cheese
• 1/4 cup plus 2 to 3 tablespoons chili sauce
• 1/2 teaspoon grated horseradish