CAPRESE CHICKEN

4 skinless British chicken breasts (about 150g each) • 2 tbsp olive oil • 2 cloves garlic • 2 x 225g packs Waitrose & Partners Pome Dei Moro Tomatoes, cut into quarters • 1⁄4 red onion, finely sliced • 125g ball mozzarella, cut into 8 slices • 300g fusilli pasta • 1-2 tsp balsamic vinegar • 1⁄4 x 25g pack basil, leaves only