Step 1Preheat oven to 180ºC. Line a large baking dish or tray with baking paper. Place eggplant, nion, capsicum and zucchini on prepared tray. Sprinkle with thyme leaves and spray lightly with olive oil. Roast for 20 minutes.
Step 2Add beans and tomatoes to the tray, drizzle vegetables with balsamic vinegar. Return to oven for 10 minutes, or until vegetables are golden and tomatoes are soft. Stir to combine, season with cracked black pepper.
Step 3Meanwhile, place 4 cups water in a large saucepan and bring to the boil. Reduce heat to low, add polenta in a slow steady stream. Cook, stirring with a whisk, for 6–7 minutes, or until thick and creamy. Stir through two-thirds of the parmesan with a spoon.
Step 4Serve ratatouille on the polenta and garnish with remaining parmesan and fresh basil leaves.