Bring a large saucepan of salted water to the boil. Add the pasta and cook according to packet instructions, until al dente.
Meanwhile, place the chopped tomatoes in the bottom of a large salad bowl. Add the garlic and olive oil, then season generously with salt and freshly ground black pepper. Stir well and leave to marinate.
Once the pasta is cooked, drain well and add to the tomatoes whilst still hot. Mix well.
Next, drizzle a little oil in a medium-sized non-stick frying pan set over a medium-high heat and add the pancetta. Cook for a couple of minutes, stirring occasionally, until golden and crispy.
Fry the pancetta cubes in a frying pan with 1/2 tbsp oil until golden and crispy.
Add the pancetta to the pasta with the chicken, spring onions and the rocket. Toss gently.
Meanwhile for the dressing: blitz together the pine nuts, basil, olive oil, garlic, lemon and Parmesan to form a pesto. Season to taste. Spoon into a bowl and stir in the yoghurt.
Pour the pesto dressing over the pasta and toss well to completely coat. Add the torn mozzarella and enjoy!