Rustic Caponata Burger - Polly-O

Ingredients

• 2 Tbsp Olive Oil
• 2 Celery Stalks, (chopped)
• 1 Large Eggplant, cut into ½" cubes
• 1 Red Pepper, cored, seeded and cut into ½" pieces
• 1 Large Onion, chopped
• 1 14½ oz. can Diced Tomatoes and Juice
• 2 Tbsp Tomato Paste
• ½ cup Water
• 2 Tbsp Dried Oregano
• ¼ cup Balsamic Vinegar
• 2 tsp. Sugar
• 3 Tbsp. Capers, rinsed and drained
• ½ tsp. Salt
• ½ tsp. Freshly Ground Black Pepper
• 3 lbs Ground Sirloin
• 2 tsp. Salt
• 1 tsp. Black Pepper
• 12 oz. Polly-O Provolone
• ¼ cup Sundried Tomatoes
• ½ cup Mayonnaise
• 2 ⅔ cups Prepared Caponata, see recipe above
• 8 Kaiser Rolls, toasted
• 2 cups Baby Spinach Leaves