Eggplant Caponata Sandwiches

Name: Eggplant Caponata Sandwiches
Ingredients: ⅓ cup olive oil; 1 medium eggplant, peeled and cut into small cubes (approximately 4 cups); ½ green bell pepper, diced; 1 small onion, diced; 4 oz white mushrooms, chopped; 3 cloves garlic, minced; ½ cup black olives, pitted and sliced; 1 (6 oz) can tomato paste; 3 tbsp red wine vinegar; 1½ tsp sugar; ½ tsp dried oregano; salt & freshly ground black pepper; baguette, sliced into small sandwiches, to serve; shredded mozzarella, to serve; fresh basil, to serve