Pit Beef Sandwiches

Ingredients

• ½ cup prepared hot horseradish
• 1 tablespoon paprika
• ½ cup sour cream
• ½ teaspoon fine sea salt
• Freshly ground black pepper
• 1 teaspoon minced garlic
• 1 tablespoon garlic powder
• 1 tablespoon onion powder
• 16 rye bread, lightly toasted
• 2 white onions, sliced paper-thin
• ½ cup mayonnaise
• 2 teaspoons dried oregano
• 1 tablespoon fine sea salt
• 2 pounds beef top round, cut into 2 equal pieces
• 1 teaspoon fresh lemon juice
• 1 teaspoon chili powder