Reuben Sandwich from New York Christmas by Lisa Nieschlag and Lars Wentrup

Ingredients

• 8 slices rye bread
• 4 tsp wholegrain mustard
• 8 tsp butter
• 8 slices pastrami
• About 160 g (5¾ oz) sauerkraut
• 8 cornichons (French gherkins), cut lengthwise into strips
• 8 slices cheddar
• 2 tbsp ketchup
• 120 g (4¼ oz) mayonnaise (see recipe)
• 1 tbsp horseradish cream
• ¼ tsp paprika powder
• 1 tbsp Worcester sauce