Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Cut the eggplant into 2cm chunks (only 300g/3½ cups eggplant is required). Put the eggplant on the lined tray, drizzle with 1 tbs olive oil, season with salt and pepper and toss to coat. Roast for 20-25 mins until golden.
Step 2 — Prep ingredients
Meanwhile, finely chop the carrots and onions. Crush or finely chop the garlic. Finely chop the parsley, keeping the stems and leaves separate. Crumble 1 stock cube* into a heatproof jug, add 250ml (1 cup) boiling water and stir to dissolve. Slice the chicken into strips. Bring a large saucepan of salted water to the boil for the spaghetti.
Step 3 — Start sauce
Heat 2 tsp olive oil in a large deep frypan over high heat. Cook the chicken, stirring regularly, for 4 mins or until golden. Remove from pan. Heat 2 tsp olive oil in the pan over medium-high heat. Cook carrot, onion, garlic and parsley stems, stirring occasionally, for 5-7 mins until softened. Add Tuscan seasoning and cook, stirring, for 1 min or until fragrant.
Step 4 — Finish sauce
Add the chicken, stock, tomato passata, 2 tsp balsamic vinegar and 1 tsp sugar to the vegetable mixture and bring to a simmer. Reduce the heat to medium and cook, covered, for 15 mins. Add the roasted eggplant, increase the heat to medium-high and cook, uncovered, for 5-7 mins until slightly reduced. Taste, then season with salt and pepper.
Step 5 — Cook spaghetti
Once the sauce has been cooking for 10 mins, add three-quarters of the spaghetti* to the pan of boiling water (if you're tempted to throw in all the spaghetti, just note the dish won't be as saucy). Cook, stirring occasionally, for 12 mins or until al dente. Reserve 125ml (½ cup) cooking water, then drain the spaghetti.
Step 6 — Get ready to serve
Finely grate the parmesan. Carefully transfer the sauce to a very large bowl. Add the spaghetti and half the parmesan to the sauce, then gradually add the reserved cooking water, stirring, until the sauce coats the spaghetti. Take the spaghetti to the table, scatter with the parsley leaves and serve with the remaining parmesan.