Best Vegetarian Beet Reuben Recipe - How To Make Vegetarian Beet Reubens

Ingredients

• 2 large beets (1 1/4 lb. total), trimmed and peeled
• 2 tbsp. extra-virgin olive oil
• 1 tbsp. brown sugar 
• 2 tsp. ground coriander
• 1 tsp. ground mustard
• 1/2 tsp. ground cinnamon
• 1/2 tsp. garlic powder
• 1/4 tsp. ground black pepper
• 1/8 tsp. ground cloves
• 1/8 tsp. ground allspice
• 1/4 c. mayonnaise
• 2 tbsp. sweet pickle relish
• 4 tsp. ketchup
• 1 1/2 tsp. prepared horseradish
• 1 tsp. fresh lemon juice
• 1/2 tsp. Worcestershire sauce
• Kosher salt
• Freshly ground black pepper
• 4 tbsp. butter, softened
• 8 slices rye bread
• 8 slices Swiss cheese 
• 1 c. sauerkraut
• Pickle spears, for serving