Preheat the oven to 400°F (200°C). Arrange the eggplant, sweet potatoes, parsnips and leeks in a single layer in a wide roasting pan. Use a pastry brush to coat them lightly with oil.
Sprinkle the thyme over the vegetables and season with freshly ground black pepper. Bake for 25-30 minutes until the vegetables are almost tender, then turn the vegetables and add the pear wedges, turning to coat lightly in oil. Arrange the bacon rashers over the vegetables.
Return the pan to the oven for 15-20 minutes until the vegetables and pears are tender and the bacon is lightly browned. Drizzle the balsamic vinegar over the roast vegetables and serve hot.
Cook's tip: If you arrange all the vegetables parallel in the pan, they are easier and quicker to brush with oil.
Variations: When quinces are in season, they can be used instead of the pears. If baby leeks are not available, replace them with ordinary leeks, sliced on the diagonal or, alternatively, use wedges of red onion instead.
Each serving: 19 g protein, 14 g fat of which 3 g saturates, 75 g carbohydrate, 13 g fibre, 522 Calories