Preheat oven to 200°C or 180°C fan forced. Line a large baking tray with baking paper. Place eggplant in a single layer on prepared tray, spray with olive oil. Bake for 20 minutes or until golden and tender. Set aside.
Meanwhile, brush the beef with half the olive oil. Preheat a large non stick frying pan over a high heat. Cook beef, for 1-2 minutes each side or until browned. Transfer beef to a rack over a roasting dish. Brush top of beef with pesto, roast in preheated oven for 40 minutes for medium, or until 65°C on a meat thermometer. Remove, cover loosely with foil and set aside to rest for 15 minutes.
Meanwhile, heat remaining oil in a large non stick pan over a medium heat. Cook onion and celery, stirring occasionally, for 5 minutes or until softened. Add garlic and zucchini, cook for 2 minutes more. Add tomatoes, 60ml (1/4 cup) water, the roasted eggplant, capers, vinegar and sugar, stir to combine. Simmer for 5 minutes or until thick. Season with freshly cracked black pepper.
Cut the beef, across the grain into slices of even thickness. Serve with the caponata, soft polenta and basil leaves.
To make soft polenta bring 4 cups water to the boil in a large saucepan. Reduce heat to low, add 1 cup instant polenta in a slow steady steam. Cook, stirring for 6-7 minutes or until thick.